someone walking into someones home and exclaiming "Geez! What an ugly sofa! You should buy a new one!" All the while, you're wearing a burnt-orange shirt and a lime-green suit with purple socks.
I don't care if you're wearing a 10,000$ Armani suit, you don't go into someone's house and start criticising his sofas. I can take criticism, but put the limit in sofas.
"Principle of Least Astonishment: Any language that doesn’t occasionally surprise the novice will pay for it by continually surprising the expert..