What is congruency?
It's when your thoughts, words and actions are aligned. It basically means being yourself. You're not pretending to be anyone you're not.
It means not having a front. Having a front takes mental energy as you have to constantly monitor your behaviour, what you say, what words you use, is this cool, is this not cool, does this fit with my front etc. Everything you do or say has to go through a filter.
If you have an interaction with someone who has this front you can feel it's awkward. That something is off. It's because there's a misalignment with what the person is doing and what the person is feeling. E.g. when you feel down and everybody is in a fun mood, then pretending to be in a fun mood is not congruent.
When we first want to get good at something, we suck at it. In the beginning. Most of us. We do the thing but because it's not natural for us, we're being incongruent.
That's a paradox. We need to be congruent but also incongruent before we become congruent.
Asking strangers on the street if you can make a photo of them might be incongruent if you've never done it or if it's not natural to you (it's not for most people by the way).
Be incongruent until you become congruent. That's the goal.