Don't get carried away with Character Expressions
I was just previewed a course I'm working on in which I used one of the Illustrated Characters. I just realized that I had changed her facial expression so many times that she started to look a bit manic.
Tip: These characters are great to use, but remember if you are expressing to the learner one component of information, try to minimize the changes to poses and facial expressions unless a dramatic change in the "story" is needed.
You don't want the person's arms up, down, up and smile, frown, angry all in 3 slides. There are times when it is warranted to drastically change the poses/expressions, but try to keep the character looking as natural as possible. This goes for the illustrated and photographic characters.
Not so good: