Mono Monday - A Collection Of Fours

Congratulations to Mono Monday on going strong for four years, so far.  Thanks to Skeena for choosing FOUR as the theme with which to celebrate.
When I used the marquetry box for my blip yesterday I discovered a set of dominoes inside.  I must have known at some point that they were in there, but had forgotten.  Obviously being black and white, with some 4s cut out of black card, there was today's blip.