Since Android app v2.1.31 I’ve noticed something about zooming with a double-tap on the image face.
Before: a double-tap would zoom-in to the maximum, with the the point of zoomed focus corresponding to the area on the image you tapped. eg, if I double-tapped a mailbox toward the bottom left of the image, the zoomed image would be focused on the mailbox.
Now: not so much.
In some situations, the focus point is maintained:
If you double-tap at or near the absolute center of the image.
When viewing a 12-sec Event (cloud clip) focus is maintained on-zoom quite accurately.
In Live View and Playback, not.
(Currently running app v. 2.2.38 - latest as of this writing.)