Nina naps on top of a Boss PC-2 “Percussion Synthesizer” pedal. From Frank Ros (@ros_frank on Instagram).

A bit about the Boss PC-2 from Vintage Synth Explorer:

The PC-2 is a very simplistic analog synthesizer featuring six controls to help shape various synth drum, percussion and effect sounds. It uses a single VCO with a triangle waveform and a knob to adjust its pitch. The sound is more often of the UFO bleep and bloop variety, although with a bit of help from the OEM manual, you can find the settings to make big bass drum sounds, castanets, tom toms, wood blocks and more. The Sweep knob can give the sound an ascending or descending pitch bend effect. The VCA envelope is limited to a simple Decay control (attack is a fixed hard transient). A simple LFO, switchable between Triangle or Square waveforms, with Depth and Rate controls can be used to modulate the VCO for subtle vibrato to crazy wobbly sounds.