Screenshots
Obviousely there are no screenshots of the UVOS server. However you can take a look here at the GUI client and additional server web modules.
VO Manager
Here are images of the UVOS VO manager application.
The main window with the groups browser

The group authorization settings

Using this panel you can setup VO access rules. Currently UVOS authorization is at group level.
The identity details panel

Identity type is an X.509 certificate in this case.
VO applications
UVOS provides a module to submit applications to a VO via WWW.
The first registration page

It is used to choose a format of a submitted identity and select global settings as personal data or requested attributes. The VO administrator can defines nearly all options available at this page.
The second registration page

Here requester provides identity type dependent data.
UVOS authentication
Other grid components (mostly portals) can authenticate web-browser users using UVOS. The browser is redirected to...
UVOS web login screen

It is possible to authenticate using email and password or even with web browser certificate if it is available.