I do not believe these 'gotcha' games shed light on anything. If it is supposed to be 'somebody's sex is not always as obvious as you think', I've already said that sometimes the sex of a person can be ambiguous, especially from a still photo with no interaction with the person.
My instinct, looking at that photo, is that they are all guys. They all look like men in drag.
And to me.
But let us be clear:
First, while humans, cats, dogs, horses, polar bears, red deer, bottlenose dolphins, humpback whales, and a very long etc., can instinctively distinguish between the males and the females of their species by a number of cues - visual or otherwise, depending on the species and the case -, the system is not infallible - no biological system is -, and in particular, it can be circumvented to some extent by means of human technology. So, yes, one can make a female look male or a male female - to some extent. The extent to which the method would work depends on the tech involved, and the specific female or male that uses it.
Second, a picture only provides only visual cues - no voice, for example - and quite limited ones at that, as one cannot take a look from different angles, for example. That very probably makes the error rate higher than in person.
So, while they all look male to me, the degree of confidence is less than in, say, a video, which still would be less than in a case in usual cases where there is no attempt to make a male look female.