The physical size is about 10x13 inches, so I was working at about 50% to fit the entire image on my monitor. This helps with the principle of working broadly at the beginning of a painting, getting the big shapes and value relationships early, and not looking too closely at detail too soon. In fact, there is not really any fine detail in this painting, I left it in a very sketchy (in places nebulous) state, as the detail illustrates.
There is likely enough here that I could increase the size of the "canvas" and spend another hour or two making a much more detailed finished painting, but that was not the intent of the exercise.
I'm pleased with how this is going, but with any luck I'll have a couple of more traditional painting classes starting in a couple of weeks, so there will be more acrylic demos to show. However, the digital isn't going away; you'll see more soon.