@espenmn: Of course not. It could perfectly be client1 or have one single client (like in a standalone installation). In such a case you should rename client2 and the paths to whatever you need (client1 or instance etc.)
In my case I use client1 for the browser view and client2 for debugging.
This is why my example (see Using IPython with Plone) assumes a zeo Plone installation with 2 clients and client2 will be used for IPython.