Make sure the color of the light matches throughout - I dont know if that is a workline but it looks like you have changed the light coming out of the door to red so make sure it is red light coming out. Also the perspective seems off, really think about roughing out your background and deciding where you want them to be standing like kyle latino said. If you want to share your references with us we could take a look at what you are trying to accomplish and help you that way - help us visualize what you are thinking.
Hope this helps!
A Cartoonist is just a lazy Animator.