The packagekit tray icon is scaling incorrectly when adapting to a changed panel size. Specifically, it seems to stay at 16x16 until the panel is bigger than 32px. Fedora uses a 24x24 panel, at which size the try icon should be the 22x22 version. This seems like a minor thing at first but the tray icon seems to be a central part of the packagekit UI, so it should look correct. More than that even: because the current action is only shown in the lower right corner of the icon as an "emblem", using smaller icons is even worse: the user has to guess the current state with the help of a 5x5 (guessed) emblem. Taking today's screen resolution into account and you will see that fixing this would indeed be important.
Created attachment 303370 [details] Screenshot This shows the packagekit icon next to the network manager and volume applet icons.
Do you mean if you resize the panel while the icon is there? I can't reproduce otherwise.
I don't resize my panel that much ;) But for common panel sizes < 30px the icon displayed is too small. I didn't test much. With the default panel (24px) the notification icon should be 22x22 but it is 16x16. I don't know it the notification icon was bigger if I had the panel, say, 26px but at least it only resized when I made the panel 33px.
Created attachment 303393 [details] Screenshot / Mockup To better show what I mean: the upper part shows what I see on the default sized panel (24px): a 16x16 icon. The bottom part is a mockup which uses the correct icon (22x22).
Surely this is a panel issue? g-pk doesn't choose the icon size at all. It just says "use that iconname".
Not sure what other apps do, but most seem to work better. Are you using GtkStatusIcon or the Egg implementation?
GtkStatusIcon
Created attachment 304788 [details] what i see This is what I see on my F9 laptop.