Странный ракурс - сверху места много, а слева модель за край вылетает, слишком широкий угол камеры. Очень вялое освещение, надо поконтрастней. Тень под кроватью явно лишняя.
just look at other models (beds) and compare with yours - angle of rendering, properly placing the model, work on a textures a bit more, they look too washy and simple, do some few more renderings, etc
Do you have reference? Did you copy existing bed or designed your own model? Bed looks weird a little, but if reference looks same - problem in materials and preview i think
