American cichlid IDs aren't my thing at all, but your mystery fish looks very familar, in as much as I saw some lovely looking Laetacara dorsigera at Romsey WOW with JDs4me a few weeks back.
its face does - but the colouration looks nothing like any of the nannacara I've seen - was at a lfs only 15mins ago and they had some larger nannacara specimens which had very little in common with mine.
I kept/sold both N. annomola and N. aureocephalus and i found they varied a lot in each batch and changed with their mood an awful lot, especially the latter. I had a pair in the tank and sometimes had to do double take as colour change made it look a different fish.
Well it's certainly not any nanacara species as the face shape and body shape are all wrong especially the colouration aswel it's clearly a Laecatara species but which one I couldn't tell you until near adult size and this one is only a juvi