In case anyone is curious, here's what happened:
I took the pics with my phone which, when uploaded to my computer, were upside down. I used the preview app on my macbook to flip the images around, saved them (at which point they were showing up as they should) and uploaded them. They all showed up upside down on the site.
To fix the issue I pulled the images up in Photoshop (at which point they were still showing the correct orientation on my computer) and used the save for web option (decreased the image size and renamed them). After re-uploading for the second time they are in correctly.