Paranormal stuff should not come into our world easily. Our reality consists of rational rules and solid laws, what keep us safe. But there is another side, a dimension where all these rules and laws are completely meaningless and all kinds of unthinkable horror become possible there. The barrier that separates our reality from that other side is called membrane, and that membrane can be shattered by fear - causing the terrible entities from that other side to leak into our dimension.
There is a scene where Elizabeth gets catcalled on a bar, but it ends up with Thiago pointing a gun to the guy, so I don't think it really counts. But if it triggers you, it's important to know!