Corrected volume path. Previously it mapped photos dir to photos/original, so the result was in the container a dir structure that goes photos/original/original. So the photos from the volume landed in photos/original/original and not in photos/originals. That is why there was an error saying that there are no images found.
Nice catch Oliver and sorry for that causing trouble on your end! I am already using the mapping like this all the time but I don't use the docker-compose.yml file. :x
Corrected volume path. Previously it mapped photos dir to photos/original, so the result was in the container a dir structure that goes photos/original/original. So the photos from the volume landed in photos/original/original and not in photos/originals. That is why there was an error saying that there are no images found.