Alexa can only recognize the keywords. Which is also why you can only choose between 3, because the device isn't able to detect anything else. After that, the c

Alexa can only recognize the keywords. Which is also why you can only choose between 3, because the device isn't able to detect anything else. After that, the command will be analyzed in Amazon's datacenter. I don't know of any smartphone or similar device that would interpret voice commands locally.