Now if you see a full-size Space card in your timeline you can simply click on it and connect to space. On the card itself, you can see info about the host, listeners, and other speakers. These cards can be also shared to Fleets in a full size while it will get minimised as a retweet.
Apart from this, you may notice a split layout that shows a certain tweets on top. Clicking on this tweet will minimise Spaces and open a normal tweet view.
During the Spaces roundup talk, devs also confirmed that they don't use any feature flags for enabling Spaces and this feature should be available to all Android users of a certain version.