|Don't look at the camera|
Inexperienced animators often do this, at least at first. We pose out our character and we think - who is she talking to? I know - she's talking to me! But in a film, or a play, or a TV Series, the camera (ie the audience) is almost always an observer, never a participant.
Part of the so-called Willing Suspension of Disbelief is that the characters acting for us don't know we are there.
|Character looks at the audience - breaks the Fourth Wall|
The trouble with having a character looking directly at the camera is that it breaks the so-called “Fourth Wall.”, the invisible barrier that separates the audience from the action that we are observing. Much of the work you need to do as a film-maker goes into maintaining the illusion that we are watching a story unfold before us, whereas in reality it is all just a contrivance.
|The character looks to screen left - much stronger|
Rules can be broken, of course, but they should be broken sparingly, and with good reasons. When you break the fourth wall, your character becomes aware of their fictional nature, and this suspends the drama.
Below is an example of strong character animation by Animation Apprentice student Victoria Bailey. The camera is offset just enough so that the character isn't talking directly to us; rather he is speaking to someone just behind us and to our right. We, the audience, are an observer, not a participant.