training is the cue. There is a leash that you can hold tight when the bird sits on your finger/shoulder, or give room for some flying, but you also have to train your bird to fly back to you in case something happens.
In our case I could take him with me up to the attic or down in the basement (we have common stairs), out with the garbage, fetch the guinea pigs from the garden or to visit a friend living nearby. Some people take their bird out when walking the dog, or on a mountain trip.
Most birds enjoy being outside, but the harness is not always fun to put on so they have to learn that wearing it means they can go out.. The Avianweb came with plenty of instructions about the different stages of training and how to use the harness. I'm quite impressed!!