To save time & simplify when displaying photos create "autoplay" global feature that allows the user to pre-configure a particular slideshow to play on app start. This has multiple advantages:
1/ Greatly streamlined & uncluttered user experience when showing customers their photos
2/ Opens the app up to wider usage (eg as a standalone display configured to show particular photos on start - great for marketing or personal use).
Should be a fairly simple feature to add.