how i know who is revealing first?

[Agent.Z]

title

[drake31]

The player who is currently winning will reveal their cards first.
If it is currently a tie, the reveal order is random.
At the top of the gameplay screen, the player whose name is glowing Orange will have their cards reveal first.

From: https://marvelsnap.helpshift.com/hc/en/3-marvel-snap/faq/38-whose-cards-are-revealed-first-during-a-turn/

To be honest, I've played SNAP for 1.5 years and I never realised the order is determined by whoever is winning

[kingts]

It is about priority, who has priority when the turn starts.
If you look at your avatars, the glowing name tag will indicate who has current priority. Though it looks why white shine to me, not orange, but what do I know.

Turn priority is given to the player who is currently in the lead, meaning, they're winning the majority of locations on the board. If players are tied for locations, priority will go to the player with the most total power.

This is alos of 20 deck archetypes I posted on another tread

PRIO or priority decks can be constructed to control matches and end game players are masters of priority. Ghost is a prime example of a priority card.

The list of archetypes is here:
https://steamcommunity.com/app/1997040/discussions/0/4353366523982739354/


So if you have priority in the turn, then your cards reveal first.

[Bloodartist]

As others said, the person who is currently winning, has priority (reveals first).

You can see this by looking at the player names: the one who has priority has a glowing border around their name.

[Perfect Cell]

If the person is winning, he gets priority
If there is a tie, the priority is randomised
Ghost loses you priority, irrespective of whether you lead the locations or not, and possibly the only card to do so, alongside maybe Sera
The one having priority is marked by a yellow glow in his name and icon

[Zlehtnoba]

And you should wait for all the beginning of turn effects to resolve (like Kitty returning to hand) before checking the glow.