Yeah, maybe... Gary did turn into a painting, so maybe it was the ending where Ib leaves the gallery without either Gary or Mary... It was really depressing to have to choose between either of the two, or neither, in the game...Hm.. Well, maybe she just.. Grew up? And.. Her memories from the Gallery were kind of forgotten due to shock or something? So she never came back? e-o
From my guesses, Gary is the most powerful painting currently in the Gallery (it seems Mary is no longer here, but I'm not sure).