If one image shows the knee guards alone, while the other shows them being worn by a person.
return one image ;return knee guards in  #1 ;return if  #2 are alone ;return other image ;return knee guards in  #4 ;return person in  #4 ;return if  #5 are being worn by #6 ;return if  both  #3 and #7 are true
['select', 'project', 'boolean', 'select', 'project', 'project', 'boolean', 'boolean']