Portraits as a symbol and the meaning of the ending
Portraits as a symbol
The symbol of portraits was the main theme of the movie. A portrait is a forgery in itself. If you look at Virgil's paintings, they were all of women posing for the painting. None of them are candid. We don't know anything about those women's thoughts, ideas, visions, desires, hopes or fears. All we know is the pose they struck, which is a forgery of who they are rather than an illustration of their authentic selves. This is due to the painter's own choice. The painter chooses to have a subject strike a pose rather than illustrating something authentic about the subject.
I'm reminded of an informal study by OK Cupid about which online dating profiles have the most success. They found that many people strike a pose for their photos, so you have men showing off their abs and women showing off their cleavage. Those dating profiles get the most attention, but most of that attention is useless and fails to develop into a real relationship. Then you have photos of someone actually doing something that shows who they are. They had an example of a woman playing a guitar, not even showing her face as it was looking down at the guitar. Then one of a man scuba diving, his face also obscured by the scuba suit. Those photos get less attention but have a much higher rate of making a real connection that develops until a real relationship.
In his obsession with portraits, Virgil was specifically choosing "forgeries" (women in faked poses, not showing their real selves). He never had any interest in seeing anything authentic about a woman, which is why he had never made a connection with one. So in a way, this is a story of "Be careful what you wish for." He preferred the fake side of a woman, what was just for show, instead of a real authentic connection with another person. That's exactly what he got.
The ending
There's a lot of discussion about the meaning of the ending and some have pointed out that he is not wearing his gloves in the end. I believe there is a key line in the movie that explains the significance of this. When he identifies a painting as forged, he says that it is still a masterpiece and worth a great deal, just nothing compared to the original.
Connect this to the main "forgery" in the movie. His fake relationship with Claire was still wonderful and it was still of great value to him, even though it turned out to be fake. It did change him enough that he could permanently stop using his gloves, and that is valuable. It's nothing compared to authentic love and connection, but definitely still worth something to him.