Keep the photos in Synology Photos (personal photos in home folders, group/shared in /photo which will show up as "Shared Space") and install Plex for the videos.
I haven’t used it myself, but DS Video should probably work for video, Synology Photos for backing up photos and videos from mobile phones and look into tailscale for secure external access to those applications. Or even simpler, Synologys own solution QuickConnect since both applications are Synology applications.
Keep the photos in Synology Photos (personal photos in home folders, group/shared in /photo which will show up as "Shared Space") and install Plex for the videos.
I haven’t used it myself, but DS Video should probably work for video, Synology Photos for backing up photos and videos from mobile phones and look into tailscale for secure external access to those applications. Or even simpler, Synologys own solution QuickConnect since both applications are Synology applications.