Actually I have a question along these lines, which I asked in another thread before without getting an answer (
here).
In short, my observation was that pictures displayed in photo shop using different display profiles with different gamma in the OS setup look the same in Photoshop (while the user interface elemets are affected by the different gamma settings). In Apples applications (Preview for example) they look differently for different gamma settings. To my impression they look most similar if the display color profile is set to 1.8, which is probably why Apple labels this as the Mac standard and assumes this setting for its applications.
To my understanding each picture file which has a color profile stored also has a gamma value stored with the profile (for sRGB it is 2.2). Color managment software will then make sure this is displayed appropriately on the screen. So if the gamma of the display is different from 2.2 it will do the appropriate transformation. This way the picture should be displayed the same on every color managed, calibrated screen.
As I said, this is my understanding. However I didn't find any documents explaining the situation in detail. So if anyone knows more I would be happy to hear about it.