It's not the product that's being advertised but the brand. Kids don't care about the quality of sunglasses. They'd rather buy the brand because they associate it with Duncombe's switch 360 flips on tranny. That being said, clever marketing would still try to connect sunglasses with actual sun.
When I started skating as a little kid, I would always wonder why videos by board brands would show footage of multiple broken boards. That didn't make sense to me. I was also suprised when the Adio video (my first one) didn't have any features on actual shoe models. Still, I grew out of that really quick and bought Rictas and Tensors although I'd heard they'd skate like shit. But what was I supposed to do when Appleyard and Creager (two of my favourite skaters) were rocking them?!