Why do my folder icons shrink on my desktop?

You can adjust the sizes of icons on the Desktop, same way you can for items in folders.

With the Desktop active, press Command-J (Show View Options in View menu). In the View Options screen there is a slider which can be used to adjust the sizes of the icons.

Note that spacing between icons may change as you change the icon size.

What are they doing on your desktop?

Performance tip: Keep the Desktop clutter-free (empty, if possible)

Mac OS X's Desktop is the de facto location for downloaded files, and for many users, in-progress works that will either be organized later or deleted altogether. The desktop can also be gluttonous, however, becoming a catch-all for files that linger indefinitely.

Unfortunately - aside from the effect of disarray it creates - keeping dozens or hundreds of files on the Desktop can significantly degrade performance. Not necessarily because the system is sluggish with regard to rendering the icons on the desktop and storing them in memory persistently (which may be true in some cases), but more likely because keeping an excessive number of items on the Desktop can cause the windowserver process to generate reams of logfiles, which obviously draws resources away from other system tasks. Each of your icons on your desktop is stored as a window in the window server, not as an alias. The more you have stored, the more strain it puts on the window server. Check your desktop for unnecessary icons and clear them out.

Keeping as few items as possible on the Desktop can prove a surprisingly effective performance boon. Even creating a single folder on your Desktop and placing all current and future clutter inside, then logging out and back in can provide an immediately noticeable speed boost, particularly for the Finder.

And it is why Apple invented 'Stacks'.

Klaus1, I appreciate your input and detail on this but I'm having the same problem, even though I keep the Desktop mighty clean. Really clean. I'm not sure this one's solved yet.

I looked into the View Options [thanks neighbor Don] and discovered that each time I toggle to the 72x72 icon size I get mini-folderettes on the Desktop. Which is to say the icons all 'shrink' way below the 72 size. All sizes below and above this show folders at correct sizes, so it seems only the 72x72-size is glitching.

Sorry no solution here but I'm narrowing it down... a restart is first on the list.

Might be your preferences are not correctly set. Go to systems prefs > dock > and run through the options.

Sorry, Savvio,

Had a brain storm and didn't read your post as carefully as I should have done.

Somehow I read it as dock icons ... 😕