The harp is a lie.

[Konachibi]

It's definitely a bow.

Harps have more than 4 strings.

Don't know how many harps you've seen but if you knew how they worked you'd know each string is a different length in order to make the different notes.

The mechanism at the top of the bow could quite simply be a string adjustment tool, to increase or decrease the tightness of the bow string.

That is all.