If I were a Christian, oh wait, I am...
Idolatry is definitely the right's favorite sin (they have even managed to make being "Christian" an idol to be worshipped), but in his case, it would have to take a back seat to pride, greed, wrath, envy, lust, gluttony, and sloth. You can also add acedia and vainglory.
The shirt is not quite the textbook definition of idolatry, though it is intended to stimulate idolatry in others (see Vanity, the self-love that others are supposed to worship).
There is no bottom to his desperate need for adoration.