We stayed at the Contemporary back in 2019 and the Contempo Cafe or Contempo Grounds were our choices for a lighter breakfast. As I recall, the pastry choices changed daily @ Contempo Grounds which was basically a 'to go' type of setup. Contempo Grounds would be my suggestion if you only want a bagel/donut/pastry to go with your juice or coffee. If you want a bit more to eat, Contempo Cafe was a type of QS service/cafeteria style setup where you chose whatever you wanted and paid at the cash register then could find your own place to sit. You did not have to have a full meal and could just choose whatever you wanted. Can't comment on if anything has changed once things reopened after the covid shutdown.
Since they have similar names, Contempo Cafe is next door to Chef Mickey's while Comtempo Grounds is on the floor where the check-in desk is located.