What is that weird thing on all iPhone 12 models?

Right there, on the right-hand side of each new iPhone 12, below the power button, there is a small piece that looks like a SIM tray but isn’t. Its color or finish is fairly contrasting with the rest of the phone’s metal frame. So, this begs the question…

What is that thing there?

The leading theory on- and off-line was that it has something to do with the 5G antenna. Remember the iPhone 12 series are the first iPhones with 5G support? We weren’t sure precisely what purpose it served, but it made sense to have some sort of a role with regards to letting those super-fast airwaves travel with the needed bandwidth through the phone’s metal frame. That theory solidified as we discovered that pictures of the iPhone 12 found on Apple’s stores outside the United States lacked that little detail. And, as it turned out that versions of the phone for non-US markets will not support mmWave 5G bands, the mystery seemed mostly solved.