Originally Posted by Pag
You could try flipping the bobbin over in the case, it might be in backwards. It does look like incorrect tensions though. If you don't have a bobbin tension gauge don't mess with it. If upper tension changes and flipping bobbin over don't fix it, find a technician with a bobbin tension gauge.
Most machines have bobbin tension adjustment in the bobbin case, usually a small screw.
OTOH, a properly wound bobbin, properly inserted and threaded shouldn't hardly ever need adjusting.