Do macs even have that though? Fraps would also capture the shadows and save them to a screenshots folder. I dont think his mac, like alot of others can even handle the lowest setting of shadows.
As a Mac user, I will go ahead and confirm we do not have print screen (or MS Paint). Fraps is also unavailable for Mac (unless someone's made a torrent or wrapper, but I have no use for fraps so I do not know) AFIAK. Cmd+Shift+3 takes a picture of the whole screen (Cmd+Shift+4 allows you to capture a specific area you outline with your cursor) and places them on the Desktop as a .png. These are built-in for Mac.
Let me pull up a screenshot I took in T:ANE using Cmd+Shift+3.

Look at those shadows. Cmd+Shift+3 will put shadows into your screenshots, fullscreen or not.
No, of course his computer can't handle T:ANE. Mine can't - even with specs double & quadruple his in all areas (no offense - but facts are facts). No Mac can properly work with T:ANE. T:ANE is not optimized at all for Mac and it was even said it probably never would be in the Trainz Mac MOW area. With shadows, the performance takes a dive.
TL;DR Macs don't have Printscreen, Cmd+Shift+3 instead works to take screens and will show shadows. Macs don't perform well with T:ANE.
Cheers,
SM