If I say, "the current President doesn't represent us," I'm obviously not talking about the whole world, or even the whole country, but the specific subgroup that I'm a part of (i.e. maybe my demographic, political party, etc). If I say, "we need to take responsibility for the state of the planet," I'm talking about everyone in the whole world, not just me and my specific demographic or political party.

It would be a lot clearer if we had better words in English, but it is usually quite clear from context. In this case, this is posted to the sh.itjust.works' "main" community, and the post specifically mentions sh.itjust.works in the image that's linked. It's pretty clear it's talking specifically about the sh.itjust.works instance.