It is the head or mask of Iron Man. It is head-shaped, with two smaller slits for the eyes. It has small protrusions for the ears on each side about halfway up the mask. There is also a frontal faceplate within the mask.
This is a Iron Man icon. We've made it in iOS style
, first introduced in iOS version 7 and supported in all later releases up until now (at least iOS 11). This style is based on thin two-pixel lines and is optimized for 50x50 px. Unlike other vector icon packs that have merely hundreds of icons, this icon pack contains 13,300 icons, all in the same style and quality.