On the surface, when we consider the difference between guy fiction and gal fiction, we might say that guy fiction is about blowing things up and gal fiction is about relationships, but if we look at a guy movie like Die Hard we can see that the main character just wants to rebuild his relationship with his wife and the bad guys are getting in the way. In other words, guy fiction is about some of the same things gal fiction is. The true difference, if there is one, is in how the protagonist solves the problem. In both, the protagonist will debate until he or she figures out what action to take, but that is where things change.
In guy fiction, the action that the protagonist takes tends to be more physical. He might not blow something up, but he might build something or go somewhere or stand in front of thousands of people to ask his girlfriend to marry him.
In gal fiction, the action is more subdued. The action she takes might be to talk to someone, even though she fears how he will respond. She may ask someone to help her with something. She may meet someone at a romantic location.
That isn’t to say that there aren’t women who enjoy stories where the protagonist takes charge of the situation or that there aren’t men who enjoy a more subdued action, but if we must draw a distinction between the two, that seems to be the difference. It is possible, and some writers do this, to have women’s fiction in which there are several explosions and men’s fiction in which there are none, but even then men’s fiction tends toward a take charge attitude by the protagonist.