Yeah, it’s just an inline resistor
A potentiometer is a resistor that you adjust using a dial. If you want control, you may want to get a PWM fan control module. There’s the Noctua NA-FC1 https://www.noctua.at/en/products/na-fc1 but that’s pretty much just a fancy expensive version, you can find the same concept for as little as $1-2 USD

















You’re using Chrome on iOS.
The address bar expands when you scroll up and contracts when you scroll down.
In your screenshot, the address bar is in the expanded state. In this state, it will partially cover page content unless you have scrolled to the very top edge.
This is not deliberate malicious placement on iFixit’s part. You are falsely attributing malice to a coincidental UI behavior in your browser of choice on your mobile platform of choice.