I wasn't suggesting otherwise but trying to identify the precise condition
you are trying to describe. I think what you're saying is that whichever
side of the train you sit on the end of the map showing Walthamstow is at
the end of the train pointing towards Brixton. To achieve that they must
have printed two separate sets of maps but they've printed them both the
"wrong way round".

I thought what he is saying is that the diagrams are the same on both sides
of the train so that on one side the diagram does indeed align with the
direction of the train. His point is that if you are only going to print
one version of the diagram it would be more intuitive to have Brixton on the
left and Walthamstow on the right to make it correspond better with a
typical map.

I think the same argument can be made for most of the lines, though there
would have to be a bunfight over the Northern line :-)