Cindy (also spelt Sindy) was originally a UK devised children's doll that was launched in the US as a competitor to Barbie. It struggled to compete and was remodelled and relaunched. It became so similar to its competitor that it attracted a law suit for copyright infringement and was dropped by its creator.
Due to the focus in its product life on unrealistic feminine beauty ideals and market competition, as well as due to its ultimate commercial failure, Cindy/Sindy has become a by-word for the pretty but unpopular, cheaper, loser model that flopped; an also-ran; a generic category filler that is apparently competitive, but ultimately no-one buys.
The term "cindy-moment" is used to describe poor strategic judgment.
Going to that job interview without first reading the position description...that was my real cindy-moment.