Just making a comparison. People are saying they don't like Zoey because they think she doesn't have depth, but they'll happily bang Josy at the start, when Josy doesn't have any depth. It's double standards again.
Depth of character is about so much more than seeing how they behave and how they react. One of the best ways to develop depth is to get into the head of the character (which you get as close to as possible here in the Interlude, with Zoey). There's only so far you can go with fleshing out a character by having them interact with the POV character. Most of what we get is developing the story, not developing the girls. The girls naturally get some development as part of that, but it's not the number one goal.
Agreed, and that's sort of what I'm saying as well - a lot of people say they don't like Zoey, and as their reasoning, they say it's because she lacks depth. In my opinion, that's just an excuse that's easy for them to land on.