This image has a door that is being opened. There are two rectangles offset of each other. The one of the left is the door and has a doorknob on it.
This Door Opened 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 5,500 icons, all in the same style and quality.