Do you mean that users of glass risk ruining their first impressions with other people? Or that the company that introduces glass (like the introducer of the Segway) risks its first impression to the people? (Because, Google hardly needs a "first" impression)
If the first public impression is that Glass is awkward and half-baked it will be very difficult for Google to generate mass market appeal. It happened with the Newton, famously mocked on The Simpsons.
Apple refined the hell out of the iPhone before making any public statements. That seems to have worked quite well. Better than the Newton launch did anyhow.