Trying to understand how "cleaning up storage" in ROON works

Hello all, I did reduce the sources (the folders) of my ROON local database significantly. And I did a “Library Maintenance” (Clean up library), and “cleared the image cache” (Clear cache).


Looking at RoonServer cache I am wondering why the folder containing the images is not affected at all. The time stamp is VERY old.
Can someone please explain this? Shouldn’t there be a reduction of the space in use?

Best, Wolfgang