Objects in the image:
category: person
category: tennis racket
category: bottle
category: tennis racket
category: person
category: chair
category: person
category: person
category: bottle
category: person
category: backpack
category: person
category: chair
category: person
category: person

Guessing-game dialogue about one of the objects:
q: is it a person?
a: No
q: is it a tennis equipment?
a: Yes
q: is it being held by the person with white shirt?
a: No
q: is it the racquet next to Nadal?
a: Yes