I re-read this quote recently and was reminded of why I so wholeheartedly practice and teach yoga.
Yoga works the whole body at any one time. If you are not contracting muscles throughout the body to stabilise or move a particular part of the body, then your awareness is on how to relax the parts which are not needed in the pose or movement. You are always considering what the whole body is doing as you practice yoga.
An individual pose is always considered with reference to what you have been doing, the preparatory poses beforehand, or the work to come (whether that is on the mat or as you resume the rest of your day).
Your yoga practice is integrated into the rest of your life so that it restores when needed, balances as required, allows you to let go of tensions which are not necessary, and causes you to raise your awareness about all aspects of your life.
In this way, yoga positively affects the whole body, your mind, and your life.