After a bit of searching on YouTube, found quite a few videos relating to the Apple Lisa, the first commercially successful GUI interface. The above video is an emulator running on a modern Mac OS. In it is exhibited some of the Apple design team's layouts and icon designs as well as some of the capabilities of the medium.
In particular the icons are very simple but are clear metaphors. Sometimes these need some additional text but in time users would have got to know what each icon meant. The statistics application is another well designed element, as is the mind map creator, though these seem pretty primitive by today's standards. Icon metaphors include an hourglass to represent a wait, floppy disk to represent external storage hardware (including floppies) and strange solid black triangles and rhombuses for warning icons.
Compare this to the BBC Micro. The above video is a welcome disc. It's more of a showcase of some of the things the computer can do, with little applications such as simple text based games and keyboard agility tests. This GUI is less advanced than the Lisa's, employing text and colour rather than graphics to navigate menus.
In fact, this computer uses a teletext system to navigate. There are small elements of graphics (a simple 'gun' like in Space Invaders obliterates some text at one point) typical of teletext. Things like the pattern generator, though, are a bit more advanced. Thus, this could be regarded as the 'next step up' from analogue Ceefax.
Finally, the Amiga Workbench is very similar to the Lisa, only is in colour. Displays some of the applications from the Mac, including a pixellated clock, calculator, notepad etc. A lot of icons here and it's interesting how many things can be conveyed by the simple computer icon. Stopwatches, hammers, pixellated printers and speech bubbles help the user navigate the various menus which, if perused via a command line interface, would be very boring.