It's a drawing of a computer monitor or T.V. with a double ended arrow drawn inside of the screen. The arrow is pointing to the top right of the screen and to the bottom left of the screen as if to indicated the diagonal size of the screen.
This Widescreen 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 5,700 icons, all in the same style and quality.