How can you tell if a group of people are engaged with something?

E.g. with the organization they work in?

People might do the actions they are obliged to do (at some minimal bar of quality) even if they aren't engaged.

The key question is: do they apply discretionary effort?

That is, do they proactively go above and beyond and do more than what they were strictly obliged to do.

It's possible to have the opposite, too.

An organization that looks healthy but is actually full of disengaged people.

A zombie.

If people don't even bother doing things they're obliged to do, the organization is in this state.

Watch out, this is a supercritical state, prone to cascading catastrophic failures.

For example, if you have an internal mandatory company conference and most employees don't show up.