In the future, So people don't have to download the image you have attached, please use the Insert Photos icon found in the Tool Bar of the Post and Reply text entry dialog window as pictured below. Since you Can't Edit your original post to remove the Attached screen shot Please include the screen shot you attached to a new reply to this conversation by clicking the Blue Reply button under your original post and use the Insert Photos icon in the tool bar. The Insert Photos icon is this one in the Tool Bar.
Since Microsoft Edge provides an option to open the image without downloading it, I took a look. I'm wondering if your computer is trying to display the text overlay that displays whatever has been programmed in the options. Try disabling the graphics processor and see if that resolves the issue. If it does then see if there is an update for the driver for your graphics processor.
Lightroom 6.14 which is no longer supported by Adobe has a bug when running on Mac OS X Big sur. It will show a big white box on top of the image if the info overlay is turned on. To get rid of it, hit the I key one or twice and it should disappear.