That is the beacon light atop the column of the Old Tacoma Narrows Bridge on the Tacoma side of the span. The omniscient 'they' were not allowing anyone on the columns of the new bridge, so we photographers were given this as our location to get our shots--forever immortalizing the official coupling of the bridges.
I had the great honor to make the acquaintance of Paul Joseph Brown of the Seattle Post-Intelligencer and Steve Ringman of the Seattle Times, both amazing photographers. I have a boatload more images from the day's festivities and will continue to upload them as time makes itself available.
When I finally came down and rejoined the foot traffic upon the new bridge, these guys seemed a popular attraction. Very entertaining for some; deathly scary to some little tikes.