I believe that this subject has been discussed here before, but I had my first experience with it today comparing Gracie to that drab guy.
I just bought a new cell phone; my first with facial recognition software to unlock the screen. I set it up in drab and it works very well.
I was dressed as Gracie today, and the unlock feature would not recognize me. Gracie has a wig and makeup and glasses that are not present on the drab me. If I remove the wig, it recognizes me, even with makeup and glasses.
I had wondered if it would see through the differences between drab and Gracie. Apparently the hair is a significant differentiator in the software programming.
-peace
-Gracie