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 HD 720p 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.