Cirno's name is pretty unique among fairy names, perhaps because it came before the pattern was established from lily white onwards, but it still follows the general theme of fairy names coming from western words. In Cirno's case, it's a corruption of 'Chill' to 'Chiru'.
Probably the biggest hint to this is Chirumiru, the old ad parody song, because it's based on rhyming Chill with Mil(k).
Ok, I'm not sure if this pic is legit traditional media or faux traditional media that looks almost real. Is there any infor regarding this particular artwork?
I believe by "'big woman' boom", the artist means a very recent trend on Pixiv to post pictures of デカ女, unusually huge women. (I think the word is read as DEKA-onna, literally "deca-woman", as in the metric prefix deca- for multiplying by 10.) This Pixiv page explains the term, and post #7638840 (a KonoSuba reference) pokes fun at the trend.
