Recognition for naughty GIFs (probably a nightmare for every programmer) left space for improvement (e.g. visit link - public warning: link contains 18+ content so please only open if you're 18 years or older https://komisari.itch.io/heros-harem-guild)
Anime/cartoon cases are indeed just harder; personally I think this is likely due to fewer telltale issues at a small-scale local level due to e.g. smooth gradients/cel shading.
From user Drago:
Anime/cartoon cases are indeed just harder; personally I think this is likely due to fewer telltale issues at a small-scale local level due to e.g. smooth gradients/cel shading.