Hi Kristof,
I do not see in the code for the ListView that it supports on-demand construction of the panels server-side, but it's obviously on-demand client side by setting the Visible property on the panel to true or false.
So I must assume that Guy's comment was made in the context of the client, meaning it's on-demand when you show it on the client, as the example image shows.
Hope this helps,
Palli