Every derivatives contract is represented by an Augur prediction market with pre-defined terms that specify the underlying asset, the strike price, the expiration, and optionality. Users participate by taking long/short positions in the contract market. More information can be found here: https://github.com/michaelhly/vegarelay/wiki
We didn't have a great designer on our team so we kind of just "borrowed" designs from Veil and Expo. Will be redoing UI/UX for the official VegaRelay.