Not giggling! Promise!
I don't know exactly what causes that mark. I used to think maybe it was a nozzle mark, but it might be from where two marbles got stuck together.
If they touch and then start to separate but their glass gets stretched out a little as they're pulling apart, then it might cause a mark like that as it gets flattened back down on the rollers.
Also, the twisting might come from it getting hung up on the machinery.
Wirepulls ARE one continuous ribbon. Wirepulls are swirls made from a fine stream of glass which folds back and forth on itself -- to the best of my knowledge.
A cat's eye gets its multiple ribbons by a different method. All the ribbons are squirted in at once -- to the best of my knowledge.