Appeal

Appeal is a visual quality that gives an animated creation another demension of realism and attracts the viewer's eyes, making them watch. Just like in a live action performance, an animated character or prop must be "attractive" and able to pass off as "real" to the audenice. What I mean by "real" is real for the animated world it inhabits. For that, the world its in has to appear real, and for that to happen that world has to be appealling to the viewer. If that world is attractive and appealing, the viewer can engage with it, and through that, the animated world seems real to the viewer.
How that is achived by individual artists and animators is what gives the animations they make their individual appeal to certian audenices, for example animations made for young children feature bright colours and cute-looking-child-like characters.

Another way of saying this is to describe appeal is to call it a character's "X-factor". If a character has got the "x-factor" then the audenice will watch the show.