The license graphs in the web administration UI are currently standard DPI PNG images. That means they get blurry and/or pixelated when rendered on a high DPI display. As everything else in the UI handles high DPI just fine, this can make them stand out in an ugly way.
Easily fixed now that we have a new version, as we can now output SVGs. rrdtool did have one bug to work around, though: https://github.com/oetiker/rrdtool-1.x/issues/1292
Looks great! Verified build 4140 on Fedora 42 in Chrome 138 and Firefox 140, and in Chrome 139 on a Samsung S25 Ultra (high DPI). These look really sharp now!