Ok, so we are starting to use Jira Service Management. We are also using the portal as an important part to communicate with customers. But the standard view of opened tickets is not user friendly (our opinion). This first image is the actual view:

So, when a new user accesses the portal, it will bring this view. But we, as a provider, would like to show the following screen:

How can I achieve that? Until now, I was unable to do this in a "global" form. I can modify the view every time I access the portal (for my user) but this is a bit useless.
How can I define the second image as the standard view on my customer portal?