This Xlarge Icons 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 4,400 icons, all in the same style and quality.
This looks like an image icon on Microsoft Windows. There are 2 rectangles, one inside the other slightly smaller to create a picture frame look. Inside is a jagged line to represent a mountain range and a small circle above this line looks like the sun or moon.