I don’t know of you’re aware yet, but the fediverse discerns between two different types of content: local and federated. Local content is hosted on your instance, lemmy.world. Federated content is hosted on another instance and federated with your server. You can distinguish between the two (on the web client) by checking if the community/thread/user has an @[instance] behind it. My guess would be that you stumbled into a @lemmy.ml community. There you’ll find a rigorously enforced “alternative” world view, as you decribed.