Despite the topic of your post, you are not looking at the Rockbox menu.
You are looking at the files and folders in the root directory of your iPod.
It appears that the "Show Files" option in the menu has been toggled from "Music" to "All".
Menu-->General Settings-->File View-->Show Files
I'm curious about all those hidden folders:
.spotlight-v100
.Trashes
._.trashes
._.Volumeicon.icns
._.ipodcontrol.icns
.Volumeicon.icns
PS - looks like I was beaten to the answer - but I am still curious about the hidden folders.