HN is social media. Social media is a spectrum. You can imagine HN like a documentary channel compared to Facebook’s reality TV, but even “documentaries” can be dopamine sinks that aren’t actually informative (or accurate). (But personally, I see lots of short and pure opinion posts here, documentaries are long and at least pretend to contain facts; so I’d hesitate to compare it to a documentary channel even with the…
You don't see pictures and videos directly on the site. It's text links and text comments and discussions. In the minimal sense of the word, even printed text is media, so it's technically true that HN is social media, but I think it's more like a news aggregator and discussion forum.
Good explanation at https://news.ycombinator.com/item?id=48445343