The video out on your receiver can have two purposes. First off some receivers have onscreen programming to send the image to the television. Secondly many receivers can be used to switch video signals so it's possible to it's possible to watch DVD, VHS satellite, etc using a single jack on the television. There is no need to send a picture from the television to the receiver.
Of of the biggest reasons to use a receiver to do video switching is because a TV may not have enough video inputs for all of the sources you want to watch, for example if you have a game console, satellite, VCR, DVD, LD, HD and you want to watch all of that on one TV, most TV's will not have enough iunputs to handle that. So you run all of the video to the receiver, then simply hook various video outs from the receiver to the TV (composite, s-video, component) as needed.