Those differences are down to colour and face. There are five colours to choose from with this 1960s-style clock, with difference faces, the slightly more stylised one above and the more traditional face you can see in one of the images below.
The clock itself is pretty consistent though and with a charm in all of the finishes, with the colour contrasting the traditional face, which has hours, minutes and seconds monitored. All of that powered by a single AA battery.
Prices vary between £20 and £25.