The few times I've had them, they've focused on how much knowledge of a particular choice I have.
When I build systems, it's incredibly common I don't know much about the topic. Especially in innovative spaces where you're literally the first team ever building a solution at this scale.
Take for example critical feedback, I can't imagine having to judge someone on that in an hour phone call.
The best teams argue quite a bit. That's healthy and reasonable. The question is if they accept, and respond to the argument, with positives and negatives, and how basically how they dance.
I don't know how to put into words what that dance is like, but you know it when you feel it. Maybe that's what you're looking for, a feeling of what that dance is like, but I'm glad I'm not making that determination on a quick basis.
Just random thoughts, thankfully I get all my employment through glowing referrals, and try to avoid interviewing anywhere without them so I can skip all of this questionable stuff.
Did the candidate just go for design without asking questions?
What questions does the candidate ask?
What areas are they asking questions about?
Can they take critical feedback on their design well?
There is a little bit of discussion on technology choice, but typically if they can justify an out of the norm choice it is fine.