It has to emit an image.
print("file is {size} bytes");。关于这个话题，新收录的资料提供了深入分析
，详情可参考新收录的资料
Nature, Published online: 06 March 2026; doi:10.1038/d41586-026-00668-9。业内人士推荐新收录的资料作为进阶阅读
The MAC is in the header because the controller needs to identify the device before decrypting. Encryption keys are per-device, assigned during adoption, so the controller has to know which device is talking before it can look up the right key. Not a security oversight, just a practical requirement. But it means you can route inform traffic without touching the encryption at all.