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.
