What Is It?

No one seems to have done a specific ‘What is it Wednesday’ for some time.  After today I expect things will go back as before, but I’m ‘stuck for a blip’ so try this one.  I suppose that ‘SFAB’ could supplement the ‘EB’ tag for a change.
 
So what is it, and why?  I’m sure some may work out what it is, but I bet no one gets the ‘why’.
 
Today I managed to tidy up a few loose ends, including getting the ‘+’ button to work on the pressure cooker timer.  Many thanks to Tedwin for giving me ‘food for thought’ which lead to the problem being solved.  Another job jobbed was the ‘what is it’, so no more on that one yet.