Our emotional reactions to marketing cues are so powerful that some high-tech companies study mood in small doses (in 1/30 of a second increments) as they analyze people's facial reac-
tions when they see ads or new products. They
measure happiness as they look for differences
between, for example, a true smile (which includes
a relaxation of the upper eyelid) and a social smile
(which occurs only around the mouth). Whirlpool
used this technique to test consumers' emotional
reactions to a yet-to-be-launched generation of its
Duet washers and dryers. The company's goal: To
design an appliance that will actually make people
happy. Researchers discovered that even though
test subjects said they weren't thrilled with some
out-of-the-box design options, such as unusual
color combinations, their facial expressions said
otherwise.91 Does the ability to study our emotional
reactions at such a specific level give marketers an
unfair advantage?

Based on the given question, we can see that the marketers are trying their best to find out the things which makes the possible customers happy at the sight of a new product.

I believe that this is a part of marketing just like taking a market survey to find out how receptive the consumers are of a particular product. I believe it is fair game as it does not violate any ethical rules or legal laws.