If they used the native instance blocking feature to "completely block" the instance that actually only hides posts from that instance.
Users can now block instances. Similar to community blocks, it means that any posts from communities which are hosted on that instance are hidden. However the block doesn’t affect users from the blocked instance, their posts and comments can still be seen normally in other communities.
I don't know specifically what the purpose of the community is but its broad topic is the Canadian comedy troupe and television show The Kids in the Hall.
The scene today's image comes from (in Season 3, Episode 13) also features the earliest credited appearance of Neve Campbell - I'd post a screenshot if lemm.ee image uploading worked :(
EDIT: Trying to embed an Imgur upload (https://imgur.com/a/xKwqmEj if the embed doesn't work)
