Description of problem: The firefox icon (unlike most of the other icons) is too big in the panel, with the icon touching the top and bottom of the panel. I realize that this is totally subjective, but I'll attach a screen shot that I think shows how the icon looks out of place in the panel.
Created attachment 114316 [details] Screenshot showing how Firefox icon appears much larger than other items in the panel.
The icon just gets scaled downward. Seems like in reality you just want padding around the image.
Created attachment 114365 [details] Firefox icon with extra padding for more gnome-panel loveliness Seems to me that it should be up to the panel to add padding around icons, but since Firefox and Thunderbird are the odd ones out, it makes sense to comply with the convention. Attached is a version of the 128px Firefox icon with a bit of extra padding around it, so it looks better in the panel.
Created attachment 114366 [details] Thunderbird icon with extra padding for more gnome-panel loveliness and here's the same for Thunderbird
Steven, thanks once again for all the great work with the icons. Checked the new ones into devel. Will be in the next set of builds.