There is a difference. This bee is a laying worker. they may think it is a queen, but there is no way to know really how developed it is as one. it is only partially developed probably. actually definitely if it is laying only unfertile eggs (drones) A queen is a regular bee of course that has been fed the rich royal jelly and thus develops. Even in what we consider full queens some develop more completely than others, I believe that is part of why there are good queens and bad queens. furthermore they continue developing and are continuously fed more royal jelly. Throughout it's life the queen releases different pheromones. the QRP and QMP for instance, Queen Mandible pheromone for instance suppresses other bees ovaries from developing, it also is believed to suppress swarming, and hive order...so this bee may or may not have developed the ability to create that, Queen Retinue Pheromone is what is believed to gather other bees around the queen...this bee shows it is creating that, but still may not have developed ovaries for creating fertile eggs. There are also other pheromones/etc too, one is put on eggs, and I think that helps the queen not lay two in a cell, etc.
I'd clip this bees leg, then put in a queen cell or two with brood if you wanted to save the hive, if not, it doesn't matter really. but all this is also dependent on time too. A real developed queen once she arrives on scene with her pheromones will queen right the hive if it isn't to far gone. I think the problem is with a partially developed queen these bees may be getting the pheromones that tell them everything is ok...when it clearly is not. But they will replace a injured queen/fake.