I think it’s milliseconds. It has no rhythm or explicit attack/decay.
It’s basically an easy way to create chord/tonal center to play over. Useful for some styles of music and also great to quickly practice scales/licks over.
There are a couple of guitar pedals that do this - Electro Harmonix Freeze & TC Helicon Superego+. I have the later and use it for exactly what you describe. Having the Aeros emulate that would make it even more incredible.