Have you ever noticed that some drawing videos feel cheap, or not quite right? It's because corners have been cut on the drawing of the images. The hand doing the drawing is usually a still image being moved around or a series of still images rotating the position. The problem is they are often in the wrong position for the thing they are drawing and they just feel wrong. The hand is not drawing the image, and you probably won't notice, but it just makes the video feel cheap. Your mind senses something wrong but you can't put your finger on it.  These videos are in violation of the Uncanny Valley Principle explained below.

For some purposes this is fine, but if you are presenting a video like this to your customers with your brand attached to it, it cheapens the image of your brand and company.

un·can·ny val·ley

noun

1. used in reference to the phenomenon whereby a computer-generated figure or humanoid robot bearing a near-identical resemblance to a human being arouses a sense of unease or revulsion in the person viewing it.

http://www.strangerdimensions.com/2013/11/25/10-creepy-examples-uncanny-valley/