Hiya, Kylen!  ^_^

I just received a Jubei Chan cel that has the same 
thing---highlights painted on the front of the 
cel.  I almost didn't notice at first; it's really 
hard to see unless you look at an angle or you run 
your fingers across the front of the cel.

It's a scene where she is wearing the lovely 
eyepatch, and the highlights on the patch and on 
her hands are painted on the front.  Maybe this is 
used to enhance the colors (no acetate in front of 
them to dull them)???

JP