I have always seen this feature in that section of the forum anytime I want to change my avatar, but "my bad" that I've always thought that clicking the "choose avatar from gallery" will open my phone or computer gallery for me to choose any picture I want from there, never did I think or thought that that feature is for me to choose avatar of celebrities that are stored in the forum system.
Good feature, though not one to go crazy about, since choosing any of those celebrities as your avatar does not make you the celebrity, or give you any special privileges, I don't see why I should consider this a cool feature, or something to even start a new thread for.