Oh... it's apparently an auto-scout cassette from the G1 cartoon episode 'A Prime Problem' (which I haven't watched since the nineties, but I'm surprised it turns out that Soundwave has another tape, since it seems like the sort of thing that would come up more often in discussions of the cassettes and thus have a higher online presence and fan-following rather than me finding out about it now). I withdraw my "why did they make it something random and non-representational". I'm not convinced that I withdraw my "instead of something... well... good" though, but I guess we'll see when it's more than a digital image.