Great proportions melt away impurities in a design. So if you have buttons and there’s too much space between them, the space between them is another element that you have to comprehend.

So if you have two buttons, you now have three objects. You’ve got the button, the button, the space. But if things are the right proportions, you just have two items, the two buttons.

And I think over a big screen, if you get the proportions right, you could be eliminating 10 or 20 different extra negative space things and things that you just have to comprehend. So it’s very soothing.

Jason during the 37signals podcast Design roundtable – Part 2 (transcript).