Running through each of the demos, it seems as though only 'penrose' and 'tree' have console/shell output.

'penrose' output is a list of information about the current rendering and has a format like:
Calculation:    0.0009 s
Drawing:   0.0074 s
Together:  0.0083 s
5 kites and 0 darts = 5 pieces.
(... This repeats with updated information for each rendering ...)

I believe that there's too much output right now to include this in the demo window's message button area. It might be interesting to show most or all of this information with a turtle.write() in the graphical area, but I think that the better option is just to remove (or at least comment out) the timing information entirely and show only the '5 kites and 0 darts = 5 pieces' portion in the message button area.

I could submit a patch for either 'penrose' option if there's interest.

The 'tree' prints a count of the number of turtles created at the end of the run. Console output looks like:
1024

I think this is not very useful, except perhaps when debugging the demo. I've attached a patch which removes this output.