Now this procedure is encrypted, but in SQL 2008 we can see it's execution plan too.
Yes, you see an execution plan that says you are executing a stored procedure.
But do you see the execution plan of what is inside the stored procedure? The actual steps that the sp performs?
No you don't, and that's because the sp is encrypted. If it wasn't, you'd see a lot more.
Try and create the same sp without encryption and then ask for the execution plan, you'll see.