As noted in this blog post, that is not supported. Specifically: Note that photos in the repeat table have attributes to extract their direction, latitude, longitude and even a user-entered description of the photo. Storing all these attributes for every one of the photos would not be possible using the multiline appearance in the image question. This is what justifies the use of the repeat.
I did try to set something up, but I really just confirmed that it doesn't work:
It will work for the first repeat item. But all subsequent repeat items will have empty calculates. Removing the calculationMode=whenEmpty will have the EXIF calculations work, but only for single photos (which is their intended behaviour).
I'd suggest the easy way out, and just add a geopoint question to the repeat, and extract lat-long from that.