Code:
mob/verb/Test1()
for(var/image/I in usr.overlays)
world<<"Found"
mob/verb/Test2()
for(var/I in usr.overlays)
world<<I:type
Problem description:
Test 1 wont find anything in the overlays.
Test 2 finds everything and reports that they are indeed /images.
"The individual items in the list may not be directly accessed, since they are stored in a special internal format. However, the list operators +=, -=, and the procedures Add, Remove, and Cut work normally. "