A hood on a short sleeved top?
This suggestion fits really well with what we see. And it give me an idea....
Look what happens when I rotate the picture about 15 degrees to the left, as viewed.
I immediately get the impression
of someone running. That curious elbow becomes naturally bent, and there's a hint of balanced movement from what little we see the left arm.
We then see (by tilting the picture even more to the left) that the 'hood' may represent the metacentre horizontal datum relative to gravity...
Lightweight hoods tend to bounce with movement to a position of neutral repose in the vertical axis. But note how there is a horizontal displacement to the right, belayed by the neck (as viewed)....just as there would be from the wind/draught effect, as someone runs or dives rapidly into a light headwind.
Ignore the grain-lines, look at how this
does start to feel like someone pitched forwards, moving fast.
And
could that be a face profile along the left-hand side, leading edge??
Does that look like a raglan sleeve join, tailing down at a lazy 45deg from the 'hood'? Is that dark blob under the 'hood' simply a trapped shadow?
Hmm....