Right now they are picked by leadership from those with existing curation experience, or those we feel would make a fair judgement.

The curation channel will soon be open for any helpie member to see (soon), and feedback can also be given for that. @helpiecake also leaves a trail of what was selected as well. We will remove anyone that abuses their role to vote effortless content, though we don't really expect too many problems with that. We'll see how it plays out. There are a few guidelines I have in mind but there's nothing official.