This is a vintage Pebble Art painting, made from a kit, that I found at a yard sale.
Here’s the box it came in. It’s called, appropriately, Mosaikit.
Here’s some info on the designer:
I was surprised that a Google search produced very little information on these kits or the designer. I also bought a second kit which was unused– it still has all the pebbles wrapped up in plastic. The painting is a guitarist from some exotic, but unspecified country.