Mark
It is your eyes, or maybe just the camera angle.
This Elm is relatively low density but fairly elastic. The width is, as I said, 1 3/8" and the thickness is 7/8". The limbs are a D section.
Perhaps I should have said that heat-treated Elm is, in some ways, better than Yew. They take less set and keep any reflex better than Yew even after shooting for awhile.