There is reliability because the results support those of the meta-analysis of Haber and Haber (2001).
It was in the pps natural environment – they were going about their normal business when approached and this suggests that it has ecological validity.
Controls over the conditions means that it is replicable and so therefore it is likely to be found as being reliable – LINK TO SUPPORT FROM OTHER STUDIES!
A photo line up is not the same as a real life line up and this means that the task itself lacks validity – the photo just shows facial features as opposed to looking at stance, build and body language.
It can only be applied to similar situations because it is not always the case the that people will have spoken to the target.