A look is the style of the invitation your guests open. There are eight, and switching between them takes one tap.
A look changes the invitation page, the card that unfurls when the link is shared in a message, the printable poster, and the header of the email. It never changes what a guest has to do — the answer is in the same place, in the same two words, in all eight.
We pick one for you from what the event is called, and it is nearly always the right register. Change it in the event's options whenever you like, including after the invites have gone out; anyone opening their link afterwards sees the new one.
Add a photo and most looks build themselves around it. Skip the photo and they hold up on type alone — none of them has a hole in the middle where a picture should be.