First: great shot!
It indeed shows several characters that would fit Red-headed Bunting.
Noticeably the rather uniform head, without any clear streaks on the crown and forehead (more obviously streaked in Black-headed). The bird also lacks darker ear-coverts, which normally appear in Black-headed.
The wing bars are clearly buffish, not whitish as in Black-headed. I count four primary-tips beyond the longest tertial, which fit Red-headed; Black-headed may have five to six primaries extending beyond the tertials.
There is no chestnut on the back and the rump, it's just brown-grey.
Not any yellow streaking on underparts, but it's a pity that the undertail-coverts are not visible.
