A vinyl record is mastered at constant angular velocity — the cutting lathe (and the playback platter) spins at a fixed RPM no matter where the stylus sits. But the groove's linear speed under the needle is v = ω·r, and the radius r shrinks steadily as the spiral winds inward, so v drops from roughly 50 cm/s at the outer edge to well under half that near the label — a real, unavoidable mastering constraint, not an artifact of this demo.
For a fixed audio frequency f, the physical wavelength cut into the groove is λ = v/f. Since v falls toward the center while f stays the same, λ shrinks too — high frequencies get packed into ever-shorter physical wiggles, which is exactly why real records suffer more distortion and lower fidelity on their innermost tracks ("inner-groove distortion"). Watch the wavelength readout shrink as the needle travels inward.
The pitch fader does nothing to the groove itself — it only changes how fast the platter turns. Since the stylus reads a fixed spatial waveform, playing it faster or slower changes how much time elapses per wiggle, which shifts the perceived pitch up or down by exactly the speed ratio — the same trick DJs use to beat-match two records.