Rover's help article is specific about the profile photo: choose something clear and well lit, about 400x400 pixels, then crop it in their uploader — that square is what appears next to the sitter's name in search results and in every message thread. Gallery photos have no stated cap, but Rover recommends at least four because the gallery is what convinces an owner to book, and the first gallery image renders largest on the profile. Sitters upload straight from a phone, so a 400x400 slot gets fed a 4032px photo and the platform throws away 99% of the pixels while the upload still takes ten seconds on hotel wifi. Compressing and resizing to display size fixes the wait and, more importantly, keeps the crop predictable: a pre-squared 400x400 avatar cannot be auto-cropped into someone's ear. Skwish resizes and compresses in the browser with a per-file readout and batch export, so a whole gallery goes up at once. Files never leave your device.