From the article, the design “mimics the look and feel of a PalmPilot to keep it simple and familiar for IMAX film projectionists”
You can certainly have a true emulator that also "mimics the look and feel" of the thing it's emulating.
If you have any actual evidence that the IMAX tool is not truly an emulator other than conjecture, we'd all be very interested.
I suspect the HN crowd's interpretation is correct that they merely replicated the look and feel. Which makes sense - Palm is still the best GUI I've ever been fortunate enough to use.