The title of this set of pieces is a well known phrase from Eastern cultures and is often credited to Japan. The origin of the title derives from an older Chinese poem by Bái Jūyì titled 寄殷協律 Jìyīnxiélǜ:
All of my friends have left me for the zither, and poetry, and alcohol.
In times of snow, moon, and flowers, I think of you. 
Bái Jūyì (772 - 846) is known to have heavily influenced Japanese literary and artistic culture  it can therefore be deduced that the root of the phrase used as a title to this work comes from China during the Tang Dynasty.
The association of this phrase being used as a musical event comes from the very origins of these three words used together that occurred in the courts Emperor Murakami (926 - 967) 
Almost 700 years later in Japanese literature setsugekka is one of several combinations of poetic topics, and refers specifically to "snow", "moon" and "flowers", a traditional trinity of beauty. There is, for example a haiku which illustrates the link between the three words: Setsugekka ichi-do-ni rniyura utsugi kana (Teitoku, d.l653) This may be translated: It lets one see Snow, moon, and flowers - all at once Oh, Utsugi. 
A little over 300 years later Peter Sculthorpe, an Australian composer, published this work. He stated that he wanted his music to make people feel better and happier for having listened to it. He avoided the full and atonal sounds and techniques that other composers were exploring, instead opting for the open form using pentatonic tonalities. This piece was composed in 1971 which was at the end of the period when Sculthorpe was heavily influenced by Asian music .
‘Snow, Moon and Flowers’ requires subtle nuances and an awareness of pulse that does not require counting, instead it should be felt. The character needs to be built using visualisation, to live and grow as the music moves. The sounds provide dynamic fluidity mimicking glinting gamelan sounds and the formal gestures of Japanese melody.
Issues that can occur in performance would include use of a non familiar instrument. The tonalities and resonance this piece uses require a sensitive pedal and a good sound board. A low priced, unfamiliar instrument may not produce the same effects. To mitigate this the pianist will require time with the performance instrument before the event. Learners who are logic based in learning and therefore struggle with visualisation may have difficulty achieving the artistic goals for this piece whereas they may be technically correct.
Form and tonality
This piece does follow a standard form but is a consolidation of musical styles. When Peter Sculthorpe chose to compose ‘Night Pieces’ for solo piano he had the full range of tonal notes and their combinations that the likes of Debussy had, alongside the building blocks of rhythmic interpretation and the natural sonorities of the instrument. I use the word sonorities as opposed to chords on the understanding a chord is three or more notes, whereas sonority refers to more than one.
The form of this piece is taken from a traditional Haiku and influenced by Japanese art. The Haiku principles used include the association of ideas through the power of suggestions. From Japanese art is the concept of study of a central theme from different viewpoints or time periods. This can be seen in the traditional painting for 3 Japanese women in Autumn,
Spring and Winter that is often associated with the phrase that entitles this piece. (Katsukawa Shunshô - MOA Museum catalogue) 
from left to right:
Sei Shōnagon (winter, snow, blue-white)
Murasaki Shikibu (autumn, moon, yellow-white)
Ono no Komachi (spring, flowers, pink-white)
Snow mimics the distance between the snowflakes as they descend to bring the freeze. The tenutos offer a glimpse of large flakes that are tumbling, giving an inkling of the pending storm, shown by the change of style in bar eleven, ending with space in between the flakes as the storm passes and the snow eases. An interpretation in the sound of Sei Shōnagon (winter, snow, blue-white). Moon indicates depth and the activity of solitude. The form of the piece leaves the impression of the thoughts and feelings of the night as rising and falling covering the full range of the modern piano moving from the depths of despair to the hope in the promise of a new day. In this second movement the openness of the sonorities brings the essence of Murasaki Shikibu (autumn, moon, yellow-white). Flowers gives us a detailed abstraction of this exquisite work’s pitch manipulations in its component sections. In moving from a semitone-rich set to a ‘black-note’ pentatonic one has a describable effect on the listener’s experience in real time as the harmony stabilises. This instability to stability coming after the previous period of darkness implies the joy and turbulence of the start of life in spring, after the winter. The joyous nature of the tumbling and rising sounds reminds you of the joy of new birth implied by Ono no Komachi (spring, flowers, pink-white).
“there are two categories of chords in Sculthorpe's music. There are those which involve at least one major seventh interval and which can usually be described as decorated triads, or be related to the triadic concept in some way; and there are those which do not contain major sevenths and are based upon a combination of tones' from the anhemitonic pentatonic scale.“ 
This can be seen in these pieces which have tonal centres of A flat which is decorated and extended. This image shows the frequency of the root notes of the dominant, subdominant and tonic chords with the tonic being A flat. The top line being the initial piece and the last line of three being the final piece.
Considering the colours attributed to these words the way the chords are extended in each section brings hints of blue, yellow and pink. The end glissando in the latter implying the cherry blossom flying away on the wind.
These three pieces are an exquisite addition to any advanced repertoire. The skill they require in touch and awareness of pulse far exceeds the notes on the page and a learner should not be deceived that the lack of notation equates to an easy journey. As with many Eastern principles the ease of appearance hides a great depth of skill.
Associated post: https://www.chrisatthepiano.com/llcm-td-comparativeanalysis
 “Japanese Title of the Game: Its Meaning Elaborated.” Serenes Forest Forums, forums.serenesforest.net/index.php?/topic/83718-japanese-title-of-the-game-its-meaning-elaborated/. Accessed 17 June 2020.
 Hannan, Michael. THE MUSIC OF PETER SCULTHORPE. 1 May 1979, p. 128, ses.library.usyd.edu.au/bitstream/handle/2123/8574/THE_MUSIC_OF_PETER_SCULTHORPE.pdf;jsessionid=4377BAFEDD353298AFD19D48D1C98837?sequence=1
 The Music of Peter Sculthorpe | Loud Mouth - The Music Trust Ezine. musictrust.com.au/loudmouth/the-music-of-peter-sculthorpe/. Accessed 17 June 2020
 “Night Pieces | Faber Music.” Www.Fabermusic.Com, www.fabermusic.com/music/night-pieces-1254. Accessed 17 June 2020.
 Arntzen, Sonja. A Shared Heritage of Sensibility?: The Reception of Bai Juyi’s Poetry in Japan. 2008, www.semanticscholar.org/paper/A-Shared-Heritage-of-Sensibility%3A-The-Reception-of-Arntzen/ed30f35cdc613bed10016252801e5e0a4d3b08bf#paper-header
 Lin, Che-Wen. “Bai Juyi’s Poetry as a Common Culture in Pre-Modern East Asia.” Nov. 2012.
 “Peter Sculthorpe.” Wikipedia, 29 Mar. 2020, en.wikipedia.org/wiki/Peter_Sculthorpe. Accessed 18 June 2020.
 https://commons.wikimedia.org/wiki/File:Shunsh%C3%B4_SGK_3_Frauen.jpg English: Katsugawa Shunshô 3 scrolls depicting women Date circa 1780Source MOA Museum catalogue Author Katsukawa Shunshô This work is in the public domainin its country of origin and other countries and areas where the copyright termis the author's life plus 70 years or fewer.