It looks like the ends you get when you don't
cut something well on a large paper cutter. 

Since oversized cels would have to be cut to size 
on a one to one basis, I would assume that someone 
did not cut the ends of this one very well. Since 
the ragid top or bottom would not be seen when the 
cel was shot, I would assume no one during 
production thought there was any reason to not use 
it. I don't think there is anything wrong with it.

My two cents