As we become mindful of our 'Head and Whole Body' one of the pitfalls is to go 'in' - to feel if we are in the right position or getting it right. Concentrating on feeling can be another form of tightening. Better to continue with spatial awareness - your whole self in relation to what's around you.
"In the World" is a cue or reminder to look out - map where you are, not go in and feel how you are.
Just a bit of science for those who like it
This becoming mindful of your whole physical self and where you are is called proprioception.
defined in the dictionary as "perception or awareness of the location, movement and action of the body."
It's often called the 6th sense.
Why ? Strengthening proprioception improves overall coordination.
"In the World" is a quick cue to get us out of that drawing inward and out of our busy heads. To become aware of the distance between yourself and the person you are talking to or the screen you are looking at; where the ceiling, the walls or the floor is; the movement or light out the window, the dimensions of the thing you are lifting, or the tool you are using etc etc
Question to ask yourself ... Do I really know what I am doing while I am doing it ?
Am I aware of my whole self and the task I am doing ?