I was a bit uncomfortable with the idea of Vogle being about to know who Dexter is by look alone, so the latest episode helped assuage those doubts (if in a blatant retcon). I also like that it looks like the show is going to criticize Vogle's black-and-white condemnation of children she diagnoses as psychopaths (though I guess not really condemnation if she practically worships them), because there's already plenty of hints about how she got it wrong with Dexter. I assume her "experiments" were also quite loony and abusive.