Oh, what version of Celestia are you using?? You should
ALWAYS state your version and OS. Indeed, the earlier
templates for the Milkyway were a standard SBb Hubble
class that I abstracted from that Hubble photo of NGC1300 in
Eridanus. It is often designated as SBbc Hubble type (Like our Milky
Way).
Meanwhile, in the CVS version that most active forum
people use, I have implemented custom templates. For the
forthcoming 1.5.0 version we now have the custom MilkyWay image
below included that I was actually referring to above. It implements
ALL published scientific information obout the MilkyWay morphology.
Artistic views like what you were citing above, we usually do
not take seriously even though they might appear on NASA WEB
pages for PR reasons...