Unofficial Skyrim Special Edition Patch

Inspecting the models in nifskope shows most helmets have a "zoom" rating of 1.0 set in their inventory marker (or they lack one entirely, which I presume amounts to the same thing). The few exceptions aren't much more than 1.1, and none are above 1.2 with the exception of the draugr helmets. The male version of the draugr helmet is set at 1.679551, and the female even larger at 1.755129. This is rather inconsistent, making them appear ~70% larger in the inventory than the ground model would otherwise appear if I understand it right. Even Yngol's helmet is relatively high at 1.247685.

I'm not inclined to consider this a bug since there's nothing to indicate they didn't actually want it to be larger in the inventory window.