Observations:

• My iPhone gets extremely hot when charging since updating to iOS 13.
• Photos says it does analysis while locked, charging and connected to Wi-Fi.
• My Indian SIM card (in router, not iPhone) has a daily data limit which is being consumed faster than expected.

Hypothesis: analysis needs images higher res than the thumbnails so has to download these from iCloud.

And it doesn’t get hot when charging with no network connection. That’s the key observation!

Wish list:

• For iOS to track data usage for all network interfaces, not just the phone’s mobile connection. The low-data mode setting for Wi-Fi networks is a step in the right direction.
• For Photos to show a progress bar or something. It’s been like this for weeks!

I love the results of the analysis. It’s finding the best cat pictures.