reusing objects on Object mission contributor

hello, i got an email from adobe about this mssion on shooting "Pair Editing | Object Position and Replacement", seemed like a fun challange and want to participate, but i dont have something clear.
the caes is for example, i have the 1st scene below 

i have replaced the orange with the apple. in the 2nd scene or an other x scene can i do the same replacment but with diffrent scene, or use the same object. for exple this is my 2nd scene below 

on top of a wall i replaced the banan with the apple, does it count? if i had put an orange and switched with an apple (like in my 1st scene) would it still count? 
Thanks for your time!