Given the problematic aspects of a "globally" available datasets and given that in many countries people are more stuck up about such thinks I highly doubt that

Given the problematic aspects of a "globally" available datasets and given that in many countries people are more stuck up about such thinks I highly doubt that this dataset contained a "representative proportion" given that you are more open about such thinks and take picture (in general). I.e. there can be a massive difference between a probability "over all humans" and a probability "over people of a given culture" as long as either the given culture is in a minority or underrepresented in given data. Given that people normally don't (knowingly) give out their private family photos when they know they culture is seen as "bad" by some people and this picture might be abused I think we can at least assume such culture(s) are underrepresented. Through we can't say how much that changes the probability.