The smartphone industry appears to be coalescing around the book-style foldable design, where a phone unfolds into a small tablet, rather than the flip-phone format that folds a standard phone in half. Samsung's latest Galaxy Z Fold, Apple's rumored iPhone Ultra, and leaked images of Xiaomi's upcoming 18 Fold all point to growing momentum behind larger-screen foldables, suggesting that this form factor is emerging as the preferred direction for premium folding phones.