Complex sentence: But the photographic figure (hereinafter referred to simply as Buddy) cannot close the window, and, as he holds the handle, is left to flail helplessly in the wind as another gust penetrates the house.
Split into simpler sentences: But the photographic figure (hereinafter referred to simply as Buddy) cannot close the window. As he holds the handle, Buddy is left to flail helplessly in the wind when another gust penetrates the house.