1.look out of the window意思是“朝窗外看/从窗口处往外看”,一般隐含看者靠窗户较近,更强调看的对象在窗外.
2.look through the window意思是“（目光）穿过/透过窗户看”,只强调看者的目光必须穿过/透过窗户,不强调其他含义.