The problem with e-mail is that you can't hear tone of voice.
Often people can "hear" a tone that isn't meant.
If it were me, I'd say WHY I wanted to see it. Like...
Jim said you did a great job with the project plan. When you have a moment, I'd like to take a look to see what I learn from it for my next plan.
I'm trying to identify who can be on a team I"m forming, but I believe a number of the people I'm considering are on the project XX team. When you get a moment, I'd like to see that plan so I can see how much time they might have available and when.
But some people write short emails. Maybe they are on their phone and typing is hard. Maybe they aren't chatty.
If this person does it often, you could write back quite politely, "Certainly, but could you tell me why you need it? That would help me know whether or when to copy you on future documents."
Student or Learner