This is not random access; the latency depends on the position of the read/write head over the spinning platter. Other analogies may be more apt. Also I guess they could have just as well built that with a Pick and Place machine out of an electronics manufacturing company, but I guess UdK has an emphasis on things being hand-made and looking artsy.
It is random access because the device doesn't have to touch every grain of sand on the way to the one it intends to deal with next. It's very similar to a spinning-platter hard drive: latency depends on rotational velocity of the platter and radial velocity of the read/write head. That the latency is quite high in this device doesn't make it any less random-access.
what you described is called "sequential access"
> It's very similar to a spinning-platter hard drive: latency depends on rotational velocity of the platter and radial velocity of the read/write head.
hard drives & etc. are called "direct access"
> That the latency is quite high in this device doesn't make it any less random-access.
the problem is not that the latency is high but that the latency varies.
from wikipedia: "A random-access memory device allows data items to be read or written in almost the same amount of time irrespective of the physical location of data inside the memory. In contrast, with other direct-access data storage media such as hard disks, CD-RWs, DVD-RWs and the older drum memory, the time required to read and write data items varies significantly depending on their physical locations on the recording medium, due to mechanical limitations such as media rotation speeds and arm movement." https://en.wikipedia.org/wiki/Random-access_memory