Circle with blue shape inside

[TheDarkWiz]

What does this indicator mean? It’s present for some choices. And for the others - there is just RB in the center of screen. Pressing it makes choices a little dark.

[Creynt]

The circles with the colored shape display in which timeline you're currently playing in. Blue means dead timeline and orange means living timeline.
The thing you saw with the "RB" button are timed dialogue choices. If you're pressing it, you are basically just skipping/disabling them for the ongoing conversation, thats why it's turning dark.

[Solid]

It indicates which timeline you're currently in

[TheDarkWiz]

Thank you guys. Is timeline something I should worry in the very beginning of the story?

[Solid]

Originally posted by TheDarkWiz:

Thank you guys. Is timeline something I should worry in the very beginning of the story?

nah. you can freely switch timelines

[Creynt]

Originally posted by TheDarkWiz:

Thank you guys. Is timeline something I should worry in the very beginning of the story?

You actually don't have to worry about it in the entire game. It just reminds you which timeline you are currently in, as you often meet and talk to the same characters. You can use the indicator to see which “timeline version” of the character you are currently interacting with to not confuse yourself.