AI in Email Windows Reveals Apple's Engineering Bottom Line for Deployment

I noticed an interesting detail: in macOS 27 Golden Gate Beta 4, Apple integrated Siri AI directly into the composition window of the Mail app, rather than popping up a separate dialog box as before. From a UI perspective, this "Write with Siri" feature looks like just a button and an input field. But from a system integration standpoint, it reveals Apple's real engineering trade-offs for deploying AI features—local-first, low latency, and scenario-specific locking.