If you want to resize a photo in Lightroom Mobile, there are a few different ways to go about it. The easiest way is to use the toolbar at the top of the screen. Just tap and hold on the photo, and then drag it up or down until you get the size you want. If you don’t want to use the toolbar, you can also resize a photo by using one of the buttons on the bottom toolbar. Just tap and hold on the photo, and then drag it left or right until you get the size you want. ..