It presents a 7x7 grid of musical measures, which you can move around in freely to play music. Each row in the grid is an interpolation between two measures in the latent space. Each column represents a decoding of the same measure for 7 different chords.
You can play the app by just improvising - moving around randomly and making shapes. Or you can play tonal chord progressions by using the keyboard shortcuts 1-7 to switch to the I-VII chords respectively.
Try the demo on Glitch.