storytelling and special (emotional) effects
Alan Lee on the creation of the shot in Fellowship of the Ring where they flee Moria: "...textures were taken from the filmed rocks and painted on to the digital ones to tie the whole thing together. It works, partly because of the skills of the modelers and compositers, but mainly because we are so misty-eyed over the loss of Gandalf that we can barely see the rocks, let alone look for where they are joined."
-The Lord of the Rings Sketchbook by Alan Lee
Good storytelling and good special effects go hand in hand. Many movies may have excellent visual effects, but a crappy story or screenplay where the world-building isn't self consistent, so the audience senses something is out of place and blames it on the effects, when actually it was the design or the screenplay or direction. Like so much mediocre art, you know something is wrong, but you can't say what.
At the same time crappy special effects may make someone complain about acting, directing etc, or superb storytelling can even cover for effects like we have in this case.