Profile Pic and Avatar

I was updating my profile picture and avatar tonight and noticed that the size of the image is bigger on the avatar one (100KB) then on the Profile Picture one (56KB). Shouldn't because the profile picture is alot of a bigger size allowed it have a bigger size limit than the avatar which is nearly double the profile picture one?

People have animated avatars I believe, which is likely why the size restriction on the avatar is greater than that of a profile picture.