That extra MM on the top doesn't affect fitmit. I compared my china ones to the oem ones and it looked just like yours. Yet it fit just fine in my 2013 I7 Imac.
If you look at the bottom of this picture II BISTRO II posted you will see on the bottom they its also extended. Just because the casing is extended by 1-2mm does not mean that it doesn't fit. Apple could have made it 1-2mm shorter because they preferred to let it wiggle around some. If anything Crucail ram is better since it's a Very snug fit. Meaning it wont move around.
Pay what you want, but their is a reason OWC ram is increasing in price and Crucial isn't. Thats because OWC monitors these forums and see the discrepancies between ran and takes advantage of users by increasing the price. They might even be posting in the thread false information like the op did without "Proof".
Mine was 1-2mm longer than the oem ram yet it fit just fine and works just fine, II BISTRO II also agree's since hes using the same ram as well. If you want to spend $60 more for 16gb and $120 more for 32Gig's feel free to. Just dont post on here saying the ram is defective because its a little longer. That just means Crucial designed it to fill the slot and apple didnt. Their hasn't been one photo of anyone destroying their 2013 let alone 2012 imac from crucial ram like the op "falsely" said that was an apples fault when he either doesn't own a 27imac or installed his ram incorrectly and destroyed it and supposably had apple fix it. The reason i say supposably is that i had my friend who works for apple search through the 2013 imac repairs inventory to see if any 27's had broken ram slots. He told me that he couldn't find 1 27 imac that got repaired for broken ram slots "Soft slots" in the USA for that issue.
I'll enjoy that extra cash to take my Wife out on a nice date. Fill my tank, Watch a movie with $$ still left over.
The op obviously supports OWC over other-brands whether its officially supported or not. Yet he supposedly bought crucial ram that was bad and destroyed his new imac.
https://forums.macrumors.com/threads/1391290/