Page edit in admin UI

H all,

I’m new to Grav. I have two separate Grav installations - the first one from skeleton and the second one - the default installation.

What I’m curious about is the Page editor in the Admin panel.

In the first installation it looks so:

In the second installation the editor looks different:

As you can see the first one looks customised. I would like to configure the second installation to looks the same.

The versions of the plugins and Grav are equal.

My question: Where is the difference in the configurations between the two systems?

The second UI:

I just found that it relies on the theme.