Viewing a
spectrogram of the second track, with the frequency axis in a logarithmic scale, reveals hidden images of James' face that were apparently synthesized as sound by Aphex Twin for the express purpose of being discovered in this manner. It is one of the few instances of an artist "embedding" images into his music (see also: Interlace -
Innuendo,
Venetian Snares -
Songs About My Cats,
Nine Inch Nails -
The Warning and
My Violent Heart) . A spectrogram of the first track, "Windowlicker", also reveals a spiral at the end of the song. This spiral is more impressive when viewed with an X-Y scatter graph, X and Y being the amplitudes of the L and R channels, which shows expanding and contracting concentric circles and spirals.