This is a Popup icon. We've made it in iOS style, first introduced in iOS version 7 and supported in all later releases up until now (at least iOS 11). This style is based on thin two-pixel lines and is optimized for 50x50 px. Unlike other vector icon packs that have merely hundreds of icons, this icon pack contains 12,300 icons, all in the same style and quality.
The image is a square that looks like a sheet of paper. There are four dashes in a vertical line on the left. To the right of the dashes are four vertical lines. There is one line to each dash. The lines and dashes are on the sheet. At the bottom of the sheet the edge comes to a point.