The picture above, what is it that makes it sexually stimulating? How is the picture functioning within the experience of a person like myself? It is the anxiety of associating symbols of emasculation to oneself. This is therefore a fetish I call MEF (Masochistic Emasculation Fetishism).
There is no inherent way in which gender signifies beyond the style “masculinity” and “femininity” happen to be differed from each other.
Historically “femininity” and “masculinity” derive from the female-like and the male-like, and this itself derives from culture coming to distinguish generalised notions of two types of bodies, in “female” and “male”. In our culture, people come to identify as female or male based on their physiological sex, and come to identify as a “gender” based on historical cultural associations related to either sex.
Regarding the fantasies in question, there are prevalent symbols and themes of emasculation which reflect wider culture, but anything perceived as emasculating is potential.
Understanding “Anxiety” & “Emasculation”.
For some, it feels as if there is a curious discrepancy setting apart overtly masochistic fantasy themes, which they may struggle to reconcile. The case is that the logic which constitutes the masochistic fantasy themes, is what also constitutes the fantasies which may not appear to be so on the surface. All of the fantasies are intrinsically and necessarily masochistic, because they are a sexualization of emasculation anxiety, of which androphilia, hyper-femininity, male inadequacy and so forth, will tend to be the supreme objects (it is for example a “femininity” through emasculation anxiety). The key point here to understand is that whilst one’s association to emasculation is manifestly productive of anxiety, a fantasy is only perceived as humiliating, in so far that a situation can be recognized as humiliating. That is to say that the association to emasculation is itself distressing, yet distress itself is not necessarily thematized in the fantasy. For masochistic sexual fetishes in general, like the spanking fetishist, our commonsense instinctively recognizes the act (of spanking) as a situation of distress, not to mention the physical pain. But for us, the association of oneself to femininity will display it’s constituting anxiety in a theme we instinctively recognize as of humiliation, otherwise the anxiety is obscured from view.
The very anxiety displayed recognisably in a situation of humiliation (right), is what also makes one's general association to femininity arousing in the picture on the left. The individual's fantasy niches will determine the visibility or explicitness of the underlying masochism.
In Addition: The Idiom of The "Faceless Man".
There are usually two main objects of concern for subjects of such fantasies, being the superficial appearance of feminine self identity and androphilia. These of course are routinely going to be the more powerful symbols of emasculation anxiety, and must be understood as such. It is not the case that one is actually sexually aroused by men or by "being female", but rather that one is sexually aroused by the very idea of being (associated to) such. Again it can not be more emphasized, that whilst these two predominant symbols of emasculation anxiety will routinely and understandably be given particular importance, they are not representative of the fetish itself, which is to say that the fetish is not androphilic nor is crossgender. In understanding our sexual experience, "androphilia" and "being female" are misleading abstractions, which obscure the actual autophilia of masochistic emasculation.