Gate parking arrangements

I came across a photo pn flickr which I found very intresting on two counts. First off is it is ALL TWA 727-100's (Look at the shape of the #2 engine's intake) and second off I found it intresting that they are all "Paralell parked as opposed to nose in. I vaugely recall seeing parking done like this on the "new" USAir terminal when I was very young in 1992? Past that I do not remember ever seeing it again. Obviously this practice went the way of the do do bird because of the obvious gate space efficency of going nose in. Does anyone have any insight as to why it was done that way in the first place? Thanks....

http://www.flickr.com/photos/denon/3106647798/