I've never heard any guess as to what it is he is writing about, but I like to think it's a science fiction/fantasy hybrid in the mold of john norman's misogynistic gor novels. I've got no basis for this--I've only swapped "hi"s with either of them--but the writing brother, who has not cut his hair or beard for years while his brother trims his, is a pictureperfect stringy uncomfortable with women type who I suspect is less likely than his brother to have spoken with anyone female other than his mother and maybe a cousin and an aunt.
the story runs, and I know this part is true, that a window popped out of an upstairs window and sat on the porch roof for 4 years before it blew down onto the lawn, where it sat another year until 1 brother, I suspect the 1 who trims his hair and beard, got up the gumption to step outside and pick it up where he leaned it against the house on the porch. it remains there. but the uncertain aspect of the story is that the only reason the screen was eventually picked up was that their mother insisted on it, or she was going to ask my female cousin, who rents to them, to come by and tell them it needed to be moved. presumably, the prospect of a woman besides their mother at the house was enough to prod them to action.