I've always loved paintings like this but I think too many people get caught up in the fact that portraits often depict a specific person. Because portraits are depictions of people many audiences and artists have concluded that the purpose of portraits is to depict people. Consequently they believe "identity" is at the root of artistic portraiture. This is the underlying thinking behind "Portrait Galleries" which usually focus on the history of the subjects instead of the artistry of the painter. I say: it's a good work of art in spite of the fact that it is a depiction of Prince Albert. Identification (of an identity) is at the root of non-artistic portraiture (mug shots, driver's licenses, etc.) but metaphysics is at the root of artistic portraiture. The same is true for other subjects like landscape (in art and non-art.) I don't care about Prince Albert and I don't think anyone else does either. It's not a work of art or a good work of art because it depicts Prince Albert or "captures his identity."