As of now, with Data Driven Pages, you have to manually add attachment photos to each data driven page individually, then export to pdf one by one. The current work flow goes as follows:
1.) collect data using collector or other web app, and attach photos to the features out in the field.
2.) bring hosted feature layer from cloud down to local machine.
3.) add GDB with feature class and attachment table to mxd, and enable Data Driven Pages.
4.) set up Data Driven Pages in the form of a report that displays each feature one at a time.
5.) then step through each page, and add the photo(which has to be opened in web app and saved to computer first)
6.) then export that single page to pdf, and do this for every feature/page.
What would be nice is to add a dynamic element to the data driven pages interface, that would add the photo attached to the feature (per GLOBALID). Then you could set up the template, and run the export to pdf on all the pages at one time. Also, if anyone has any code that accomplishes this, that would be great to. Thanks!