Wear cosmetics and emotes
Open the wardrobe, equip what you own and use the emote wheel.
Press Right Shift → Cosmetics to open the wardrobe. Everything you own or that is free for everyone can be equipped there, and other Hexa Client players see it in real time.
Hold B for the emote wheel. When someone near you does an emote, press J to answer with the same one.
Cosmetics are only visual: nothing changes how the game plays. "Show cosmetics" in the menu hides everyone's cosmetics if you prefer.