Example?

ecological

If the recognition algorithm works the way I believe it does, it's looking for silence before the keyword, indicating it's the start of a question and "Alexa" is the subject:

e.g. "Alexa, how many people live in Germany?"

and not

"I should talk to Alexa about ordering ten new televisions."

Can't think of a lot of sentences that start with "ecological".

yeah, I was half joking.

That being said, I think you can name the echo whatever you want. Maybe the people in the commercial just chose "Alexa"

The system default is "Alexa". Says so right on the web page.