When a Tribemate purchases Brawl Pass, Tribe Egg will get a +10% enhancement boost applied to every Tribemate.
The Tribe Egg can stack up to 100% for a maximum od 2x Enhancement.

When a new Brawl Pass start, the current Tribe Egg doesn't get enhanced, it affects only the next Tribe Egg event. This is done so that people wouldn't leave and join into different Tribes in order to open multiple Enhanced Tribe Eggs.