Entitled Travel of Light, the video depicts rays of light blasting away to form a photo of a person looking upward (check out the video at 0:36 seconds for some full Bifröst action). The video description also links to Nikon's relatively empty landing page for this campaign.
The video hints at possible mirrorless cameras, which Nikon already stated it would make by spring 2019. As for this video in particular however, a Nikon representative could only confirm that this video is "about a new product that is currently being developed."
In the meantime, rumors report that Nikon will launch mirrorless cameras by the end of July and will ship two models by August: One is a 25-megapixel variant that costs $3,000, and another is a $4,000 45-megapixel variant. They are Nikon's answer to the Sony's well-received A7 III mirrorless camera.