@Vree
this is all based on personal “art exprince” also, some school.
take it all whit a half grain of salt.
portrait means fully colored/shaded 2d handdrawn pics stuff were the
focus is one or more characters (it can also aply for statues of characters)
that means, no landscapes or lanscapes whit miniature chars in the distance.
it cant be lineart, only-hard-shaded lineart or vectors. however, it can be used on quick detailed character sketches. and it shouldnt have any readable text, at least not at first glance.
imo a useless tag whit too many variables to be eficient.
bust goes for art which focuses on the smaall head-chest-shoulders area of the body
aka: it shouldnt have a waist or anything below that.
both of these are barely a bust, the former is too short(its more like ‘head’) the later is a bit too big (arm & hands)
profile is a perfect shot of the side of the face.
like here, celestia is on profile, luna, is not.
it should be taged to any pic that has at the very least a half of the focus on a character that we can see in profile.
i also did some cleaning on each tag’s 2/3 nwest pages. portrait is by far the most misused tag.