This Bookmark icon is a responsive icon. This means that it's optimized for four resolutions, from tiny 16x16 until highly detailed 80x80. The style comes from the latest Microsoft Office, which makes it perfect for any Windows applications, in particular, those with ribbon toolbar control. Unlike other icon packs that have merely hundreds of icons, this monster icon pack contains 15,000 icons, all in the same style and quality.
The image appears to be a flag or banner. The basic shape is a rectangle with the long sides standing vertically. At the bottom instead of a straight line to close the rectangle the center point of that line dips up like a triangle is missing from the bottom of the rectangle.