hm, it does look like a cross betw. the sinu and fingerleather/devilshand/lobophyton
I've never seen a sinu look like that with its polyps retracted. It usually retracts completely (looks smooth, no variation in color), becomes a brighter green, and scrunches its arms in.
On the other hand, the lobo gets a green coat when its retracted, and you can see brown dots where the polyps should be. So my devils hand looks like your picture.
I've just never seen a lobo have such thin branchwork similar to a sinu.