Food Science: Salmon? Looks like. You see how the she dipping sauce required? So putting garlic has no uses, but you have to buy and cut it? Have you ever thought about those things in life? Waste money, waste time.....

 Lemon and onion, I have seen them using it to deal with the meat types of food.

So probably for those meat has itself smell. 

But for flavor...You are eating a chulk of the fish like that, you need a dipping sauces !

A lot too !