50mm f/1.4 Model Lens?

I've noticed that on most of the Canon DSLR product shots the 50mm f/1.4 is attached.

I know it's a sexy lens that can produce mighty fine images, but any ideas on why it's that specific lens?

It's small and unobtrusive.. Doesn't get in the way of viewing the body, while still giving the viewer and idea of size and appearance with a lens mounted

I think there's more to it than just the physical aspects. 50mm prime has long been the "standard" lens for 35mm/ff, and the 50 1.4 is accessible to most photographers. It's in between the nifty and L in cost, AF, aperture, physical size, and IQ.

If you look through the Canon specs on many of their cameras( in manual), they use the 50/1.4 as the "guideline" for viewfinder magnification, metering range, and flash guide number.