I'd imagine Bryce doesn't feel some egotistical need to put himself on his own albums. After putting so much of yourself into your music--the writing, playing all the instruments, producing, composing, taking hours upon hours perfecting that vision you have in your mind to be recorded--I'm assuming he doesn't want to take lightly what the art should represent. That art comes from him so as opposed to just throwing some words on a design or letting someone else take control of his work--he puts himself on it.
Sorry, long post, I know. I think this is his best album art so far.