@apol this appears to now have a camera icon indicating that there is no image. If you'd like we can probably change it to something with the Breeze icon as suggested in the bug report with text along the lines of "No screenshot provided". Or is the camera icon enough?

Best would be imo to define/override the "no image" case on the ghns side
to a) reduce loading times from server and b) also be flexible whenever a
new icon style is wanted on the Plasma side.

The image should be cached on the client, so the a point should at least be heavily mitigated. But, yes, adding a mechanism to knewstuff to use the current icon theme's "no image here sorry" icon when that default image is returned would likely make sense anyway, i'll see what we can do about that :)