Android: Delay dropbox upload intentionally
As stated already, one solution would be to use an app that lets you synchronize with dropbox.
I personally already used Dropsync. It works flawlessly, however, the free version only lets you sync one main folder. So that was not really an option.

The solution I just came up with is making good use of the Tasker app yet again.


tell Tasker if the camera or gallery apps are running and mobile data is enabled, disable mobile data.
then as exit task (to be executed when camera/gallery get closed) re-enable mobile data.


Dropbox will then upload all the shots I did not delete right away using the camera/gallery app.