Script Editor's hidden debug mode?

I was rooting around in Script Editor’s bundle resources when I noticed some familiar toolbar buttons…

set the_icons to {"SEDebugImage.tiff", "SEStepIntoImage.tiff", "SEStepOutOfImage.tiff", "SEStepOverImage.tiff"}
set se_path to (path to application "Script Editor" as string) & "Contents:Resources:"
repeat with an_icon in the_icons
	set an_icon's contents to se_path & an_icon as alias
end repeat
tell application "Finder" to open the_icons using (path to application "Preview")

Now what are those doing there? Was it just over-reaching on the part of the interface designer, or are we finally going to see this in ol’ SE?

Also, on a somewhat related note, while rummaging around in the system files I also happened upon the set of graphics that are used to label items in the dictionary viewer. The icons were helpfully labeled with titles, and since I could find no other legend to describe these, I felt it may be of service to someone to list their names on my site:

Interestingly enough, the list doesn’t quite gel with the key I found in sdef editor’s help file.