When using Firefox for Android, and browsing Google Images, I can select one of the images to open it in a bigger view, at the top of the screen. When I do this, I can go back to browsing by either clicking Google's "X" button on the top left of the image (which works as expected), or by using Android's "back" button. When I use Android's "back" button to do this, the image will correctly close and go back to browsing mode for an instant, before opening back up again. Once the image is opened again, I can interact with it as expected, but if I try to go back, either by clicking the "X" or by using the "back" button, I will be taking to the page I was in previous to the Google Images browsing page, as if Firefox hasn't realized I have the image selected. Steps to reproduce: 1. Open Firefox in Android 2. Open google.com 3. Search for any term 4. Click on the "images" tab 5. Select any image 6. Press the "back" button on your Android phone 7. Note that the image has closed for a second and then opened back up 8. Press either your phone's" back" button or the "X" button on the image 9. Note that instead of being taking to Google Images, you've been taking to the page before that, Google search.