What is the left for?

Posted on

I was musing on this issue today, with iPad to hand. This resulted (double clicking on the image and then double clicking on the next window you get should deliver a much bigger version) :

Screen Shot 2016-08-07 at 21.06.00

And don't jump before checking that what you say I have missed cannot fit into the categories I have used. Some are quite broad, but that was the purpose.

Comments are welcome, but please make them constructive.