It's a circle with a bow above it. The bow is pointing downwards and is wrapped around the circle about half way. It kind of looks like an eye with an eye brow.
This Tap icon is made in Material Design style
developed by Google. This style is based on extremely simplified shapes, thin two-pixel lines, and is optimized for 24x24 px. Unlike other vector icon packs that have merely hundreds of icons, this icon pack contains 6,000 icons, all in the same style and quality.