How chopsticks work?

[Saphiriors]

I explain better. When someone uses chopsticks, the animation first shows the other choices and then plays chopsticks. Is there a reason for that?

Moreover, I wonder how IRL one can hide he is using chopsticks in that turn. I have no hints!

[Meeplelowda]

I explain better. When someone uses chopsticks, the animation first shows the other choices and then plays chopsticks. Is there a reason for that?

Moreover, I wonder how IRL one can hide he is using chopsticks in that turn. I have no hints!

In an IRL game, you place one card face down as usual, then at the last second before the reveal, you declare that you are using chopsticks (I refuse to say "sushi go" and do not teach that to new players) and select and place another card face down.
Here is how the rule is worded (2014 edition):

Here's how it works. Choose the first card you would like from your hand as usual. Before everyone else reveals their cards, call out "Sushi Go!" and take a second card from your hand, also placing it face-down on the table. Then all players reveal their cards.

Before passing hands, put the chopsticks card back into your hand.

The rules don't state clearly when (if at all) you are allowed to change your selection before cards are revealed, so I suppose that upon seeing you use chopsticks someone could change their card.