Premiere Pro Fix

I have a video I exported. When I took the video a box camera was showing on corner that shouldn't have been. To cover it up I just created a shape to cover it and color matched the shape with the very white background. On the big screen it plays fine. On mobile, the shape can be seen. However, when I try to take screen shot of the shape, in the screen shot, you can't see it. If you go to the website shown in the attachment and click on the play button on the large image, once it gets to 01:49 (counting down form 3 minutes) you will see the triangle on the left, but only if you're on your mobile. On the big screen, it doesn't show. Can you help? I have the raw PP files.