If I were to rely on my own sensibilities, I would say this is not the Theotokos and is more likely a deceiving spirit or something else that an investigation could probably uncover. Purposeless visions of the Holy Virgin are against Holy Tradition and according to the Saints of Orthodoxy are rare and solely reserved for those who can accept such visions in the utmost humility. Why would Christians undermine the unique nature of such true visions by claiming that so many thousands of people can have visions of the uncreated glory of the Virgin? Plus, why would the Virgin want to become a Youtube celebrity anyway?
I personally lean towards this supposed "vision" as being a hoax, mainly by observing the video posted above which allows for it to be recreated. Towards the end of the video the light dissolves into a singular point as if it has its origins in that point which seems to be attached to the top of part of the church through a rod (view this at the 4:32 mark). I think this just may be an interesting case of laser or some other light technology.
Also, if this "vision" were authentic, why then doesn't the Holy Virgin walk around the roof and bless people from all four corners or something. She just stagnantly remains in that single space and dissolves into a point that is attached to the building by a rod.
Such things make Christians lose their credibility, and I have to side with the Muslim and skeptic opinion here, unfortunately, that it is a hoax.