Complex sentence: The film cuts forward to Shaun, who's looking at a picture of his dad, who died in the Falklands, in his bedroom, contemplating the incident and brooding about what has happened, with his mother Cynthia assuring Shaun that Milky will be all right.
Split into simpler sentences: The film cuts forward to Shaun, who is in his bedroom looking at a picture of his dad who died in the Falklands conflict. He is contemplating the incident and brooding about what happened, with his mother Cynthia assuring him that Milky will be all right.