My experience is several years ago, but seeing as no one has responded yet, I'll throw it out there. I don't think much has changed.
You can pick up a little credit card size QR photo card from any of the roving photographers or ride photo counters. That eliminates the need to waste time in the morning going to the photo shop at its busiest time.
Any other photographers / ride photo counters will add your photos to that QR card throughout the day. You can keep using that card or add new cards for the length of your photo package. You can have multiple cards going - helpful if you lose/forget yours, or if your group splits up.
At any point before park close you will need to go to an actual photo shop at the front of the park to activate your package though, and they will link your QR card(s) to your account, and your photos will show up on your online account.
Once your photos are in your online account, you have unlimited access to download or print them. I believe the access lasted for 2yrs and they sent an email before access ended.
There are also photographers with some of the meet & greets, and automated photo spots (the Delorean Time Machine, the Jurassic Park Jeep). If you go to Volcano Bay, you can also link everyone's tapu wrist band which will net you pics from the slides.
It's probably a good idea to check your photos and make any adjustments while the package is still active. They do/can add some cute little borders to certain shots, and some little stickers (Universal logos & such) but some of mine were not oriented properly with the actual photo, which was a drag. They can edit them same day they were taken, not sure if they can change them on following days while package is still active. They couldn't edit them once my package expired.