[XeTeX] XeTeX, XeTeXpicfile, and counter-intuitive behaviour

[Philip TAYLOR]

The behaviour is even stranger than I thought.
Used unadorned, \XeTeXpicfile introduces a significant
right shift for all text that follows it on the current
page; concealed within a \centerline, all is well yet
concealed within braces the artifact remains (so it
is not a scoping issue).

"Curiouser and curiouser", said Alice.

** Phil.