The Expresso menu is a great way to express yourself using a variety of facial expressions and to access some quick actions.
Opening and Using the Expresso Menu
The Expresso menu can be accessed by pressing and holding the point/drop button on your controller (see here for the full VR controls to see where this is on your controller). You can exit the Expresso Menu by releasing the button.
To select one of the Expresso options you can use your pointing hand to swipe either one of the 3 emote menus, or to a quick action menu.
Swiping left, right, and up will lead to various facial expressions while swiping down will give you some shortcuts for opening your watch menu, taking a picture with the Share Cam and selecting the push to talk option (if push to talk is enabled).