I haven't analyzed the ZARA app in detail. But at first glance I see the difference in the positioning strategy of both brands. Zara seems to play more on emotion and slightly higher quality/ fashion feel. Logically it makes sense the app to have a style guide kind of look I guess. Personally I don't prefer that information architecture and lack of order. But also there's a chance that I might not know what I'm talking about 🤷