The Desk Top is an abstraction in computerese of the top of a person's desk. There's a clock, a calendar, a bunch of open folders, a cup of coffee, and a cup of pens on it.
Each of us has our own style of covering these desktops with our projects, our to do lists, and our lunch.
In practice, a computerese desktop equates to a tiny desk (about 19 inches square) with wobbly legs. To fully simulate the computer desktop in real life(ie the Mouse), you should only use one finger when working at your tiny desk. It was a neat abstraction in its day, but it's beginning to show its age.
Is the idea to accurately and convincingly simulate a literal desktop, or provide a convenient way to do stuff on your computer?
The desktop is not an abstraction but a metaphor. A simple name was required for the place where folders and files can be put. The metaphor may have been inspired by visions of a literal simulation, but these days, it's just a convenience. Compare CommandLine.
I'm waiting for large, pressure-sensitive LCD screens, say 24 x 36". That could be a desktop. DeskSizedDesktop
I rest my elbows on my desk. Oops.
Can it also have scanning built in? and tactile feedback, so you can feel the edges of windows etc. With pressure sensitivity and tactile feedback, the keyboard could be done in software as well. It would pop up whenever you did a 'Home Row' gesture on the desktop.
Our computers, these days, are usually on our desks, or mounted on the wall in front of our desks, or on our laptops, which are usually on tables instead of laps.
The metaphor of a DeskTop fails now.
My calendar is still on the wall; I use the one on my computer only to schedule future appointments.
-- ChrisGarrod