Judge - the use of reading lights only still leaves the cabin much darker than full lighting. QED
I know the 'doublebow on the left' is certainly the BA brief, and it was done to enable sufficient 'spare' tape to allow survivors to be tied to whatever if appropriate - symmetrical tying does not leave enough spare. I don't know if any other airlines use it. It may appear 'comical' but there might be times when it would be a good idea?