Not jblow, but here are the major differences from my perspective.
The photographers are paid for their work upfront. They are not doing it for free, they just need to ask for consent before using the photos for any secondary purposes outside of their immediate project. Apple is not paying anything upfront and won't pay for any streams in the first three months a customer is using their service.
Taylor Swift also does not get to use the photos without consent from the publisher. Unlike Apple, she does not get to use them to make money or as a carrot to attract future customers.
Finally the photographer's art would not exist without Taylor Swift. I don't think it is unreasonable for her to therefore claim some joint ownership of the work. Unlike Apple which only plays the part in distribution of music and not the creation.
You are right, that does change the dynamic. However, I think that is more a dispute between the photographer and the publisher than the photographer and the musician. It isn't Taylor Swift's fault that the photographer agreed to do commission work without any guarantee of being paid.
The photographers are paid for their work upfront. They are not doing it for free, they just need to ask for consent before using the photos for any secondary purposes outside of their immediate project. Apple is not paying anything upfront and won't pay for any streams in the first three months a customer is using their service.
Taylor Swift also does not get to use the photos without consent from the publisher. Unlike Apple, she does not get to use them to make money or as a carrot to attract future customers.
Finally the photographer's art would not exist without Taylor Swift. I don't think it is unreasonable for her to therefore claim some joint ownership of the work. Unlike Apple which only plays the part in distribution of music and not the creation.