Great Western Coffee Shop

Probably being thick but...why is this mentioned so much ?

Everything that arrives 'forwards' at Penzance leaves 'backwards'.

Or is it to do with platform markings like those for bikes in HST power cars being only at one end of a platform - does only one end take bikes ?

only one end does take bikes now and that is coach A ,although the power cars still have bike space in them

Are you thinking about the "this train is in reverse formation today" announcement? HST's normally have first class arriving at the buffer stops at Paddington first (wouldn't want those premium payers walking to far now eh!) so when a train happens to have the Standard class arriving first it is in reverse!

I'm fortunate enough to have an employer who sees fit to reward senior executive staff with 1st class travel, as this enables them to get some work done during the journey. Nevertheless, I invariably welcome trains travelling up to Town in reverse formation since my onward destination from Paddington is best reached via the Hammersmith and City line, which is furthest away from the station concourse.