Moving the odrive folder is part of the free version. It is possible to move the odrive folder to an external drive, as you've seen. As mentioned above, we don't officially support this or recommend it because it can cause adverse side-effects, like sync delays, additional CPU overhead, disk churn, etc. That being said, it is your system and you are free to do whatever you feel is best for your own use case.
For your pictures from the memory card, if you copy those to the odrive folder, they will be uploaded automatically.