Comment 5 for bug 1201280

ok, my suggestion was a bit careless, sorry.

repeat is an event function and hence has to be used in the handler.

def found(event) :
    print "found it"
    event.repeat()

onAppear("1433207314491.png", found)
observe(background=True)
while True :
# sequential logic here

So I guess, the observe is for handling some popup or other situation, that comes up asynchronously during your worflow in the loop. So if you are sure the onAppear-target has vanished at the time you issue the repeat(), using this without a wait time is ok.