Created attachment 4353 screen Now is not that the icons in the tray and the icon as activators are not the same size. This causes a conflict panel settings and icons against one another. The best solution would be to add the options you can set the icons - the size - just like every man for himself where he wants. As the existing icons on the panel added when the activator is about 2 pixels smaller (if they had a border of about each other) of these icons in the tray. And it does not allow the optimal set of icons to the activator on the panel. And if it is dependent on the theme gtk2 is no one theme will be changed to eliminate the difference of the icons (tray = panel activator / icon). Therefore, the best solution seems to be adding the regulation of the size of icons on the panel, where tray icon would remain unchanged in terms of size.
Not sure if I understand you correctly. You *can* adjust the icon size by adjusting the panel size - most[1] icons will be automatically resized to fit it nicely. You can also try using another theme, or modifying the one you're using. Some themes add a lot of padding in Gtk buttons so the icons are needlessly small. Better themes (greybird, for example) treat the panel differently from other windows. [1] Some icon sizes cannot be changed - this includes, for example, these in systray (they are not icons at all, just windows from other applications embedded in systray, so we have zero control over how they look like).