Why does Adsense ask you to put a code after the head tag on one profile?

Question

Google

Hello toaster, I registered the site in the Adsense system, they accepted me and that’s what hangs there prntscr.com/cq6qqi
At first glance it may seem that everything is simple, but here’s the thing, it’s been like this for 1.5 months, I don’t receive an email that, well, like we did not find our code on your site or something like that, I have to wait half a year until my site is checked for code. And why is it necessary to insert the code immediately after the head? It’s just that my friend recently also made himself Adsense, where they ask to place the code in the old fashioned way somewhere on the page and not necessarily after the head, here is a screen from the site, the code is prntscr.com/cq6tic but there have been no changes for 1.5 months.
Here is what is written on a friend's account prntscr.com/cq6vhr as you can see the difference is huge.
Why are the rules different for me?