This icon looks to be an unfinished square. Instead of having the top sides connect, there is a gap that has two arrows with curved tails going into it. The arrows are pointing down.
This Feed In 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.