This game uses the old-school method of storing entire pictures and showing them one at a time really quickly for animations. This can run poorly on some computers/phones so the various "animation patches" floating around have attempted to remedy this by replacing the pictures with videos.
I made my own when I made my Android port. I pre-applied it to the "optimized" Windows build and it enables incest content as well.
Edit: It looks like the animation patch linked at svcomics is actually mine, minus the incest patch.