This person should be fined

It is a shandy yes, but more common with lagers or ales instead of stout [beers] such as Guinness

Guinness is a dark creamy beer from Ireland and loved throughout the world. It is sometimes mixed with Harp or another lighter beer to make a Black and Tan which has layers like the picture. The idea of mixing it with a sugary citrus soda is unusual and likely pretty nasty.

Guinness has a really low specific gravity and some kind of quirk to the carbonation. That’s why it’s so dark but it feels so light when you drink it.

I once drank Budweiser and Dr. Pepper mixed and it wasn’t terrible.