Do you know how I transferred my photos to the capsule last time?
I had to:
1) Connect iPhone to Macbook (via USB cable, not wifi)
2) Run shitty Photos app
3) Copy all pictures to the capsule...well, NO! Select 50% of pictures (because I don't have enough space on Macbook), press Import all selected pictures (don't forget to check Delete after import!)
4) Wait, wait, wait
5) Then drag all imported pictures to the capsule
6) Wait, wait, wait
7) Then Google where Photos stores all photos
8) Delete them
9) Repeat for the rest pictures
It is even more difficult if you want to transfer YOUR music from iPod to the capsule. I had to make a backup, then google backup location, then copy everything manually (bad thing is that all files have cryptic names).
Apple loves to say that all their devices are integrated with each other. What I want is, for example, to press 'Transfer all pictures/music/whatever to Time Capsule' and just wait until it is done (via WiFi).
It's not an Apple product, but "Plex" can transfer your photos to your own harddrive/library if you buy the pro version. You can for example run the Plex server on your Mac or on a Raspberry Pie, and then let Plex synchronize your photos to your Capsule over wifi or 3G.
Edit: it also allows to delete them directly after import