the assistants will intervene and beg me not to disturb her further. “Look at her, she’s reading,” they’ll whisper to me, in a tone of wonder, as if I did not have eyes"
This is obviously the Guardian version of the Mn "and all the bus applauded".
Or maybe they meant "please don't disturb her because we saw what a temper she had last time you were in and refused to buy the plastic tat from the corner and we've only just repaired the damage from last time."
I've been in many bookshops over the years, with 3 reading dc, who would flop down happily reading for as long as they were left. No one has every said anything like that, because there were far too many other children doing the same to comment on one child.
They also spend far too long on screens. It isn't mutually exclusive.