A short note to avoid confusion. The guy without a shirt wearing sunglasses is called Dude. But he calls everyone dude (note the lower case 'd'). So when it's Dude (with a capital) it's the guys name and when it's dude (lower case) it's a descriptive term, like 'guy', 'mate' or 'hey you'.

Unless it's at the start of a sentence. Then dude becomes Dude but it's not his name. Maybe I should have put more thought into this...