Comparison between iPhone 3GS and iPhone 4 screen

Technology Retina Display implemented in the new iPhone 4 seems to be more than a simple marketing shot, and this can be seen very clearly in the image above where we have an iPhone 3GS and an iPhone 4 next to each other, and I'm sure you can find out for yourself which one has the better screen.

Although for many this technology does not mean much, here the pictures seem to prove the opposite and I am sure that when you hold an iPhone 4 in your hand you will realize the enormous difference between the quality of the image displayed on the screens of the 2 phones. I for one am amazed at how well the images look on the iPhone 4 compared to the iPhone 3GS and I am extremely curious to hold one in my hand.

Looking at this picture, what do you think, is it just marketing?