Windows 10 Mobile's Photos and Camera applications got updates in the Store overnight, at least for devices on the Redstone branch at the moment, with the main improvement being that deleting batches of photos is now instant - or at least instant in the UI, with the actual local and OneDrive deletion being relegated to a background task, i.e. while you get on with something else. Long overdue and very welcome. Also new in Photos are a hook-up for printing to a Windows 10-compatible wireless printer and an option to view a 'Living Image' as a still photo. Plus bug fixes to both applications, including that most annoying Photos scenario, where a recently taken photo is shown as always processing, with streams of animated dots forever.
[Updated to mention that all this seems only to be available for devices on the Insiders Redstone branches at the moment - though I can't see why the version shouldn't roll out to general Windows 10 Mobile branches soon....]
Deleting a batch of photos used to take forever, waiting while the OneDrive versions were also zapped - now (right, see the annotation top-right) all this is passed off to a mostly background task while you get on with browsing your photos and doing other things.
Inherited from the desktop Photos app is full printing support, though note that the list of compatible wireless printers is still not absolute; (right) if all else fails, you can print to 'PDF', though this is pretty pointless, being just another electronic format!
The living images improvements are:
you can also now select a particular 'frame' from a living image by hitting the 'edit' control and then 'Save photos from living image', in just the same way as you'd save a frame from video footage.
you can view a living image as a 'still', or vice versa, using a toggle on the '...' menu
Showing the new edit option to 'save photos' from a living image and (right) toggle how such images are presented when browsing through photos on the phone...