It's a logo for HD 720p reduced to the numbers 720p. The numbers are enclosed in a square that borders it. It looks like a 720p logo that you would see on a normal Smart Television set.
This is a HD 720p 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 13,900 icons, all in the same style and quality.