They think the old man,
currently at the coffee machine,
is taking ages.
This briefly creates a 'bromance',
like an association between species,
the Taxi driver and the builder,
a connection across the trades.
The old man,
oblivious to the goings on behind him,
picks up his coffee and goes to pay.
The taxi driver addresses the machine,
the builder moves up the queue waiting his turn,
and the brief 'bromance' ends.