Why is this considered a brilliant move?

Cool move I found, white to play and win

Guess my Elo (horses are at the vet)

I just got my first brillant!

Apparently it wins one point of Material

Why is this a mistake?

White to play, capitalize on blacks mistake for a crushing advantage

Queen sacrifice for a mate in 2

That face when the strategy is going accordingly

This was a long game

Fork Dinner time

Easy but satisfying Mate in 1 that I found in a game

How is this a check mate? Am i missing something