Right now, the only way to this site is by going to the questions tab, and on the right side pressing one of the featured/hot questions on this site. This isn't very useful and can be a hassle. Even more than that, someone put a "Main User" button on the Meta side, but not the Main side.
\$\begingroup\$ What was weird, but is now fixed, is that I couldn't see the "Meta User" in your second picture, and I forgot about the first picture. I don't know what that third picture is supposed to mean, I mentioned it in my question. \$\endgroup\$ Feb 11, 2018 at 23:34
Meta is also available under the ? button (help and other resources).
My profile on Code Review has a Meta User button. If yours did not, perhaps it was because your account had not posted to Meta? Or some reason like that. Perhaps you did not have sufficient reputation (5) to post on Meta. I.e. I'm not sure you are describing a Code Review/Stack Overflow difference so much as a behavior related to your account.