Hi @Martin Shuler
If you are running Excel for Microsoft 365 Apps or Excel for web, you may try the Notes function.
Here is a thread, you may have a look.
Add a pop-up picture to a cell in Excel 2019 (Please note, Notes function is removed from Excel 2019 at present, but steps are the same.)
But if you are not a Microsoft 365 Apps subscriber or you are unbale to use Excel for web. You may need the VBA code to support this request. Please check out the following thread.
Hover preview over excel image link
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