The main use of the new markup feature of Google Photos app is for screenshot editing. You can highlight a part of your screenshot, add markings and write notes on your screenshot. You can also use it to draw doodles on your photos. Here is how to get the new feature on your device. The new markup tool in the Google Photos app is very basic in features, with only a few tools for drawing and doodling. You can choose a pen (for writing and drawing), and a highlighter, along with a choice of seven colors. There’s also an undo button and a clear button if you make a mistake.