So the product is named "Echo" but you ask it questions by calling it "Alexa"? That's just odd.
What's odd to me is that Alexa is way more common name for humans than Siri is. I wonder what false positives will do for households with a human Alexa.
I'm not considering the iPhone/Siri example the same. Siri came much later after iPhone and is not the primary mode of iPhone operation.
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".
That being said, I think you can name the echo whatever you want. Maybe the people in the commercial just chose "Alexa"
edit: "wake word" I guess.