Search keywords in image files that I added on my Photos app on my Mac.

Hi Epifeny, let's jump right into this! 

I'm not sure if this is possible, when using a third-party app, but I know it's not possible on our end. 

In order for this to work, you'd need to tag your file once it's uploaded through Dropbox. You can see more about this here. 

I hope this helps! 

I would much rather do my bulk/batch work on my PC and just have Dropbox backup/upload the files with the additional metadata already embedded.

This way I can have my partner use the tags I've added as metadata, to search and find files over the entire Dropbox account.

Hi Epifeny, currently, it wouldn't be possible to do as you're asking via the Dropbox service, as those tags are only for Mac devices.