Stenzek gets a ton of abuse from the emulation community that is undeserved. I remember when he made PlayStation 2 emulation on Android possible with AetherSX2 under another username/alias, a massive technological leap, and the community treated him like trash. Moves like this are just in response to the entitlement and poor behaviour that some people directed towards Stenzek. Yes it sucks for the rest of us who behave appropriately online, but none of this would be happening if others treated the guy with respect in the first place.
From what I’ve seen, it’s a QR code that links to a website which logs your IP address, along with other details.