There is nothing to do from the stuff, mentioned in ‘Next steps’.
As soon as you are able to use the demo, leaveit as it is.
You got your pubnub keys and edited the three files mentioned in the guide ?
If yes, remember, you have to start the assistant.py script manually.
If you do this from a terminal you will see if it runs successfully.
Here is an example :

./assistant.sh
pi@mirrorpi:~ $ pubnub subscription completed
hello from python!!

If this looks good, that window shows you the activities.