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 the HD 720p icon for Windows 10
. Here we go. Optimized for 32x32 px, these are the simplest icons in the line style. Downloadable formats are PNG and SVG, among others. Icons8 icon pack is unique in providing a huge number of icons designed by the same team of four designers who create the new icons every working day in the same style and with the same quality. Same cool as the Bat Face, huh.