Hi Booswalia!
As you continue to work with Jeddah's materials, you will become intimately connected with these states. Expansion tends to be a place of openness, possiblity and potential (as contrasted with a contracted state of fear or limitation). Harmony is an experience of balance, serenity and calmness (rather than one of overwhelm, strife and struggle). Light is buoyant, effervescent and open clarity (as contrasted with darkness, constraint and lack of clear vision).
These are my adjectives, but you should be able to use those as a jumping off point for your own experience of these states. I wouldn't over-labor this, because the more you work with Jeddah's materials, the clearer this will become.
All the best!
Wendy
