The design of the craft widens in height and width from front to back.
More specifically, the roof of the craft slopes downward
from front to back, but the raised, curved side extensions have a slight rise
from front to back.
That's already widely known as the mock-up was built with a measure of forced perspective to the design to make the 22ft. exterior look bigger than it really is from certain angles. But it's also integral to the design as it's mimicked on the filming miniature. But on neither is there any indication that the nacelles (or the access hatch) had any taper to them.
That's what I meant to say -- not that the Galileo
's nacelles had a taper (they obviously don't), but that the shuttle itself (the main hull) narrows from back to front.