Hmm, despite my earlier words, and while thinking about it, I think that's probably appropriate for the sitting President. While not military, he is the commander-in-chief; but then again, civilian control of the military is supposed to be one of our principals. So I dunno, could see it either way. Couldn't say with any authority, though, with regard to what official protocol should be there.
And really, there's more than enough valid criticisms of our current President that we can skip the small stuff