Objects in the image:
category: person
category: person
category: tennis racket
category: person
category: person
category: person
category: person
category: clock
category: person
category: tennis racket
category: person
category: person
category: person
category: person
category: person

Guessing-game dialogue about one of the objects:
q: is it a person?
a: No
q: a ball?
a: No
q: a racket?
a: Yes
q: federer's racket?
a: Yes