The reverse can be just as true. By recognizing the type of cake it is, you recognize that the shapes in it are strawberries. In those cases tagging them strawberry just because "it's strawberry shortcake so it has to be a strawberry" is kind of tossing junk into the strawberry tag.
Also sometimes the strawberry is cut off, sure can recognize it as a strawberry after the fact of recognizing the cake, but it'd be debatable if we really want those kinds of posts under strawberry.
Example: post #5267697