Yes, you may notice that.

But not all click and send parcels are processed as you process yours.

Not all scanning occurs in the same way yours are scanned.

C&S lodgement processes do not always require that a parcel has a label affixed to complete a scan of the consigned parcel label into the system.

Parcels can be handed over for lodgement (IMO probably more frequently with a large amount of parcels or one/several boxes full) with the consignment being calculated and scanned by AP from the documentation printed from C&S that accompanies the consignment, as they include the bar code.