The Image Comparison addon provides actions to visually compare images. You can select an element and visually compare it with a local stored image. This addon will also allow you to compare two images that are locally stored on your machine. You can use "Take element screenshot" action to locally save an image and the compare actions to compare different images. For more details on what this looks like and a step-by-step tutorial, you can check out this article.
If you have any issues with taking screenshots using the actions in the addon on mobile devices, try closing your keyboard.