5 minutes isn't a good long while though, and the image burnt into the screen for 10 minutes isn't quite temporary ghosting. It's not really an issue because the AppleCare means they should get an immediate repair/replacement. The real tragedy of this story is that the OP had such a ballache getting it sorted. Disappointing as Apple's customer service should be better in this instance.
Update from earlier today.
So they told me that if I could replicate the problem, they wouldn't have a problem with replacing the screen for me. They were not able to replicate the problem with the screen persistence test that they do. HOWEVER, I opened up a few windows and left it here for a few minutes, and long and behold - it was there. After having him show it, he went again and did the SAME persistence test 4 times, and made me wait. After more tests, he confirmed that it actually does happen. After he witnessed the replication of the problem, he then went and tried it on another iMac in their store. He came back to us about 5 minutes later and told me that because it happened to the one in the store, they will have to refuse to fix or replace it because it meets Apple's "specification". He then later stated that he heard of this issue before and that some iMacs have it, and some don't. I asked him "If you had to pick which you'd rather own, would you own one with this problem or one without?" he told me he'd rather have the one without the problem. I then told him that if he's favoring one device over another, when he acts like the problem is okay then there obviously is a problem. I even asked him that if I could bring in 5 iMacs without the issue that if they would consider repairing mines. They still said no. I was checked into the Genius Bat at 8:00AM and I was there since 1:00PM.
The superior that I was on the phone with earlier gave me his extension and number. He told me that the problem is currently being escalated, and based on the pictures we gave him, they will determine if I have to send mines in. He also says that I have excellent proof of the problem, and that they will have to do mail in service for a whole entire new iMac replacement.
I've spent well over $10,000 at that particular Apple Store in a little less than two years, and they'd rather lose a customer than satisfy a customer with a problem that was addressed, and proven. The person that tried to help me at the store was some completely different guy, and I had to explain and replicate the problem all over again, which was why I was stuck there all day. The manager completely ignored me and went on his way with other customers. Also, the superior on the phone told the manager to email him the picture of the ghosting on the iMac screen that was happening, and he sent him a glared pictures of the iMac, which was pointless.
That Apple store needs to stick with what they say instead of changing different things up every time I prove something to them that they think I can't. Let me also note that my case number said that my screen would be replaced if I could physically show them that ghosting does exists. The superior on the phone asked the store to replace my unit for me and they even refused it. I even asked them to replace the screen and if it did in fact happen again, then I wouldn't ask for another replacement service - they even denied that.
So now I'm hoping the superior I was on the phone with will solve this issue. Fingers crossed.
Here's a google link to the store:
https://www.google.com/search?q=apple+store+cherry+hill&oq=apple+store+cherr&aqs=chrome.1.69i57j0l5.3228j0j7&sourceid=chrome&es_sm=91&ie=UTF-8#lrd=0x89c6cbad4ca521a1:0xfed7d60615898c4f,1
It has a 3.3 star rating, and almost all the negative reviews, I can relate to.
