My humble opinion is that favs are good, but they could use some upgrading. Favs don't give much information to the artist without a comment and sadly many don't comment. What comes to my mind would be an easy two clicks faving. Click one: fav. Click two: pick up the biggest reason for faving from these examples given (composition, colours, theme, etc. etc.). And the artist could see some sort of index of given favs and reasons. It would give more to the artist and would not be too much work for either criticizer or artist.
Personally I like advanced comments and critic more, but this would give a new meaning to favs.


