Oh ok. sorry about that... I didn't notice the 'coming out' effect. Here's the code for it:
body
{
background: #FFF url('logo.png') no-repeat 150% -125px;
} I snooped at the code *hungs head in shame* and played around with the values. The % should be greater than 100. The -125px is the background's distance from the top (you can set it to 0 if you want to observe the behavior of the background as a test subject).
The % value specifies the horizontal position of the background. 0 means left and 100% means right. Since the value is greater than 100%, the background is partially hidden (the rightmost portion of the background is in 115% of the browser's width). For example, if your monitor is 1000px, the background's rightmost part is at 1150px. So 150 pixels of your background is hidden.
Since 115% of 200pixels is less than 115% of 1000 pixels, resizing the browser to 200pixels is like positioning the background's rightmost edge to to (15% of 200) or 30 pixels from the 'end' of the browser. This brings down the 'hidden' portion of your background to 30 pixels (from the initial 150).
I don't understand the exact concept of which exact value to use... For example, if it's really the right-edge that's being positioned, setting a value of 0% should hide the image completely, right? But it positions the background to the left. =/
If you want to play with the values, try a negative %. It hides the background when you increase the browser's width. =)
Marked Solved 
It was fun learning too... 
