As we are a Kirigami application, this makes use of the Kirigami icon item, which in turn allows us to use more types of icons, and not just QIcons. This also allows for remote icons (once a patch has been added to Kirigami to allow for this, and until then it fails gracefully by simply failing to load any icon).
I did consider adding a loader-based fallback system to this, but that would put a loader inside the listviews, and i'm not sure it really gains us a great deal... If we instead accept Kirigami 2.1 for this (or even 2.0), DesktopIcon will happily accept the url, and if it is the pre-2.2 version it will simply show nothing for those entries that request a remote picture (that is, the code will be much more pleasant to maintain when compared to such a fallback system, at the cost that the visual experience will be at worst slightly degraded). I think it is an acceptable cost, if we can trust that Kirigami 2.2 is released sometime in the not too distant future.