Hi and welcome.
This probably isn’t something specific to the Windows Player - rather the CMS settings might need some adjustment.
There is a image size limit and a resize threshold which you can configure in CMS settings which determines the maximum sizes of images that will be sent out to Players.
The little cogs in your screenshot mean that the image uploaded is waiting for resize - meaning it triggered one of those limits.
You can find out a bit more about that here: https://xibo.org.uk/docs/setup/resizing-images
Thanks