Edit: The Big Day is over. For those of you (I'm kinda guessing there were quite a few) who weren't sure what this was (and for everyone else too, thanks for being a sport) (Happy??) April Fools! (please tell me you already knew this!)
Based on other posts by the author (they have posted AI generated art before, and attribute when it's not AI generated), I'm pretty sure this is AI generated.
The fine print in the mastodon toot:
Fine print: Happy first of the fourth!
Says Happy first of the fourth, implying first of the fourth (month - April), which is what I based my own hint that this was an April fools joke in a veiled way.