Confused with resolution of the Macbook Pro Retina Display

Hi there,
I get a little confused with what the resolution is for the Macbook Pro Retina Display.

This is my understanding and hoping someone can correct me if I'm wrong...

So when you are using the desktop and applications such as Safari and Chrome, the resolution will appear as 1440x900 due to the icon pixel doubling technique apple uses to prevent blurring or the screen appearing too small.

So does this mean when you open up a photo, your only seeing it as 1440x900 and not the native 2880x1400?
OR
its only the desktop environment which runs 1440x900 but everything else will be in full resolution 2880x1400.

I was thinking that i would like my desktop to be readable but seeing photos in true retina display is what i would want it for.

Hope this makes sense.
Thank you in advance for your help.

Thank you charlieegan3.

Makes sense.

So its always showing 2880x1400 however the desktop has been enlarged to be viewable.

Thats awesome!

Cheers Dangerous Theory.

Yeah I didn't think about that.

I guess, i was more concerned with the retina display showing everything 1400 resolution as apposed to the native 2800.
I was thinking whats the point of having the ability to run 2800 if your running everything 1400.

This might be an easier example of what I was trying to get across.

I boot up the macbook pro retina display.
I go to a web site http://www.whatismyscreenresolution.com/

It says your macbook pro retina display is running 1440x900. (Did this in the Mac store on the retina display)

I then go to my photo and open up a photo.

Will the photo be 1440x900 or 2800x1800?