I've noticed that there are Oyster readers near the deep-level DLR
platforms at Bank.

I can understand why they have them on the platforms at Stratford, in
case one arrives from National Rail and crosses the platform to begin
an Oyster journey.

But at Bank, you must have either started an Oyster journey already (on
LU or DLR) or else just come through, or about to leave through, the
barrier line at the entrance. So what are the deep-level Oyster
readers for?

Just curious really. It never occurred to me to look for readers there
in the past, and it hasn't been a problem.