Apple computers use another color profile different than the one used by Windows. Therefore, images are displayed differently in a Mac computer than in a Windows machine.
Processing a picture in Photoshop in a Mac in order to show it on Internet, maybe is not the best idea right? The resulting image in your screen will not be the same many users will see in the website you want to show it.
Which would be the best way to deal with this problem?
I notice a big difference in the blacks and whites. Mac computers usually display images with a bigger contrast.