Hi Myst!
I think it's probably a blemish that happened in transit to the store. I can't see it that well.
I would like to make a suggestion, though. Whenever you buy a new orchid, no matter where from, I suggest that you keep it away from your others for about a month. Is there some place that has the right light and temps that you could isolate from others? You just never know what might be lurking and it's best not to have anything spread to the others. That's what I always do and it's paid off more than once.