To me, other people and the outer world are one and the same, because other people are in the outer world, and the outer world contains other people.
Let me explain this a little better by looking at the houses in the others/inner world part of the chart: Cancer, Leo, and Virgo. Cancer is not yet in the outer world, but beginning to be aware of others from a feeling point of view: becoming aware that something ELSE is out there, with feelings. Leo is aware of others but has a wall that separates them, just as the stage separates an actor from their audience. The audience is THERE, but the Leo energy is not out there in the audience, in the outer world, with them. Virgo is ALMOST ready to meet others, but there are a few last minute "touches" before they are fully ready!
After all THIS focusing on others from the INNER point of view is complete, the person is FINALLY ready to step OUT into the world and begin to relate (with Libra)!
So the others/inner world part of the world is about becoming increasingly aware of others (i.e., getting "out of our shell").