Joe Reads are informal segments where host Joe will read a short snippet of an article, website or creative work. The hosts tend to agree upon doing them spontaneously; they are rarely planned segments.
Joe Reads are usually discrete sections of an episode, read in an idiosyncratic way that incorporates deadpan delivery, gradually increasing agitation, and meta commentary.
They most frequently appear during times when the other hosts are occupied for whatever reason and Joe elects to fill the silence.
Lars generally opts to edit these short segments, not for content but to add bizarre post-processing effects. One example is a filter he puts on Joe's voice with a reverse echo effect, giving the whole read an unnerving, spacey vibe.
Most segments on the show can be argued to have a "purpose" in terms of the cohesive structure of the show. Joe Reads can perhaps be considered an exception to this idea, existing solely for the introduction of chaos.