Based on the theme and time of posting, this is likely a design for Yuki Miku (2024). Haven't found any matching entries though. The artist has a Piapro account but no uploads on it. Considering post #8243229 which is also likely an entry for Yuki Miku (2025), these are probably the artist's own designs. Either they posted it on Piapro and subsequently removed it or they never submitted an actual entry and just drew it for fun.