Requested on art stream by Shroomy (Feb 25, 2023). Spin-off pic based on his fic: "The Misadventures of Derpy's Boobs", check his ponepaste here: https://ponepaste.org/user/Shroooomy

Since in the fic she was fired from her job as mailmare, she decided to start her own mail service, independent from the equestrian government, which is why she is wearing a blue uniform. Also the bras, custom made by Rarity, that she wears aren't always of appropriate size or quality, Derpy just can't afford it.

Original Post Date in Source: Feb. 26, 2023.
Just to make this clear for taggers, Derpy is NOT anthro in this image, it is based on the fic linked above where she is a normal pony that got the "unfortunate" (depends on how you view it) potion effect of having chest tits, while still having a large pair of crotchboobs, see the fanfic tag for more.