This was a virgin queen that emerged in an incubator the evening of Wednesday, July 28th.
The nuc was one of 6 made up from a colony in which the queen (and enough combs/bees to make up an observation hive) was removed on Tuesday, July 27th.
Virgins were introduced into 4 of the 6 nucs just after they were made up (on Saturday, July 31), and the remaining 2 were introduced the following day (Sunday, August 1) as all 6 nucs were transferred into different boxes. One virgin was also introduced to a newly made up split (from a queenright TBH) also on Saturday, July 31.
5 of the 7 virgins were still present on Monday, August 2nd.
The virgins were emerged in an incubator (into glass vials), and fed and kept warm in the incubator.
The last 2 virgins were transferred into JZBZ plastic cages on Sunday night (August 1) as the vials were getting dirty inside. It was clear that by this time the virgins were much more mature (faster runners, more wing flapping, more energy, etc).
Sam Comfort introduced these final virgins to the 2 nucs that did not appear to have queens with just a puff of smoke at the entrance before opening the colonies. As you can see, the bees in the nuc seem happy to see her.
Note that none of this was done under ideal circumstances (it was during a conference with 50+ beekeepers watching and an incubator that was being transported from building to building and its temperature fluctuating).