Yes. Most modern caskets are equipped with a raising and lowering mechanism that adjusts the interior "bed" on which the body rests.
This adjustment requires use of a little tool called a casket key. The funeral director can insert this tool into a slot, usually located on the head end of the casket, and crank it until the bed has assumed the ideal position for viewing.
When the lid is to be closed, the key can again be used to lower the bed down, and to lock the lid into place.