This patch is an alternative to D2806. Instead of increasing the size of the right selection panel to have an additional row, this patch reduces the size of the icons (from 40 to 32 pixels), to be able to display more entities (4 × 10 = 40 instead of 3 × 8 = 24).
The advantage is that this allows for future additions and mods, while not taking up more space, which is especially important on low resolution screens.
The disadvantage is that due to their smaller sizes, the icons become slightly harder to identify, especially on high resolution screens.
How it looks in game: {F1469891}
Related: D2051.
[EDIT] While at it, the middle and left panel files are also properly formatted, for consistency and to make them more flexible for future tweaks and mods. Effectively the only visible change is that instead of 30×30 pixels, the small icons in the left and middle panels are now 32×32 pixels, the same as the new size as those of the right panels. Otherwise these two panels will not look any differently.
See also https://wildfiregames.com/forum/index.php?/topic/28525-larger-panel-or-smaller-icons/&tab=comments#comment-401080