Copy Image from QtWebEngine based browser does not copy proper data to clipboard

When copying an image in a browser using QtWebEngine, the clipboard data generated is not proper and cannot be pasted to i.e. Microsoft Paint. When viewing clipboard data with a spy-tool, the copied image data differs a lot from data that is copied from i.e. Chrome browser, even when the image is precisely same from the same page. The Spy-tool also cannot show preview of the image, since the data is not there / is not correct.

Steps to reproduce:

• Run qtwebenginewidgets demobrowser (or cookiebrowser) example
• Go to any page that has image
• Right click -> Copy Image
• Open Microsoft Paint
• Try to paste image

Expected result:

• Image is pasted

Observed result:

• Paint throws error message: "The information on the Clipboard can't be inserted into Paint."