He is grumpy. He is oozing grumpiness from every pore. It is not a cold day, by any stretch, but he's hunched into his feathers, his crest is down, and he has the air of a bird having a serious sulk.
He's molting, which can't help. His breast feathers are a washed-out salmon, with grey around the edges, like the salmon got left out too long.
It is probably difficult to be cheerful when you're molting. Important bits of you are falling off, after all, and I'm sure that there's a nagging worry in the back of the little bird brain, and you find yourself thinking "Will it grow back this time? It's always grown back before, but what if it never comes back? Will I be a bald-bodied cardinal for the rest of my days? Will the other birds laugh at me?"
Of course, it's probably a lot worse for the Kojak cardinals, who molt all their head feathers at once.
Regardless, Grumpy the cardinal is not goin' anywhere. Activity in the yard goes on around him, but he has staked out his sulking spot, and he's not movin', damnit.