A couple of years ago I checked in at MAN for my Jet2 flight to Pisa and was asked, "Are you carrying anything for anybody else?"
"Yes , I am" I replied, as indeed I was. A bag full of home comforts for a friend based in Pisa for a year to study Italian at the university there.
Yes but you well know they meant were you given stuff by a 3rd party to carry on.
I agree though that the question can be interpreted a couple of different ways and depends on the mood of the Pax and Checkin operator.
Best was going with a couple of mates on a flight and everyone getting asked did you pack the bags yourself.
One guy to his enternal shame never got to answer as another mate stated loudly, "of course he didn't his mum packed it for him", the look of Pity from the checkin girl said it all.