It looks more like a "lehr kiss" to me. That's when 2 pieces of glass riding on the belt through the cooling tunnel (to put it simply) touch or "Kiss" each other, 1 loses a little glass, the other gains it. It happened all the time with insulators.
Well it looks interesting. When the parison is delivered to the final blow mold, it is hung by the transfer bead of the neckring. Some times the hot glass will swing before the final blow is made, this can create some discrepancies in the glass thickness in The bottom heal area. Often called heal tap, if the corners are to thin, and a tap on the corner can break the glass containing ability if it breaks. If the parison makes internal contact the bottle can end up with a bird swing. If it is a press and blow bottle a spot of glass can stick to the tip of the plunger and cause a spike of glass on the inside bottom of the final blown bottle. The study of marks and causes - has been part of my glass study for years. RED Matthews