In certain posed shots, his triceps look good -- though more for their conditioning and striations rather than for their size.
When he's not in that particular pose, his triceps look very small and flat.
In the FDB and lat spread, they also look extremely small (relatively speaking) and flat.
Munzer's small forearms and weak triceps are certainly overshadowed by excellent biceps and delts. It's an unusual and not well-balanced look. Points for conditioning, but not for shape.