Half a dozen of one, six of the other.
(Not Asda, but ours are exactly the same)
The handset makes a 'suggestion' which is usually based upon a text search of the item name, sorted by distance from the expected place of the item on shelf.
However, the staff member is under pressure to pick as fast as possible, and can override & basically grab whatever is nearest.
Either one can produce spectacularly stupid substitutes.
That's not even starting in wrongly labelled trays and items in the wrong tray