I just ran into this issue today when resizing some images and exporting them as JPEGs. After I realized that the size that I had exported them at wasn't correct I reopened them to see that AP was showing the original resolution. I then used the Terminal "file" command to confirm that the resolution was showing the value I exported them at. This was definitely confusing and I didn't realize what was going on until finding this post. Is there a reason this hasn't been addressed yet? I'm sure this isn't a big deal for most people, but I'm just curious as to the reasoning. Thanks for your time.