On the PC, a splash screen is a little window that pops up while the program is loading and initialising. These tend to be large and colourful. The phrase splash originated within the Apple camp - though I don't exactly know why is is splash...
Quite a number of RISC OS programs offer similar things. I've used one, affectionately known as Genesis, for years. But the underlying feature of most of the RISC OS initialisation thingies, and most of those on the PC too, is that they are boring!
It is an animated sparky effect. You know, like those plasma balls. The one currently in QuickVoy
looks similar to the one shown above, only it has five elements.
I did code a nice many-element sparky with more realistic sparks that actually followed your mouse pointer (similar to how the plasma balls spark up to your hands). Unfortunately it put a non-acceptable delay on loading QuickVoy. Fine if you want to marvel the graphical effects. Not quite so fine if you only want to connect to the Internet!
Those of you who play chess via email and have never heard of Quake will be pleased to know that you can turn this future off.