Circuit inverts at high frequency and is unity at low frequency
This looks like an all-pass filter used to shift phase without affecting the amplitude.

From Wikipedia, LINK:



The transfer function is:



So the magnitude can be flat, because the pole and zero cancel, but the phase exhibits a shift, I.e. the filter has unity-gain magnitude for all frequencies (until the op-amp runs out of steam). The filter introduces a different delay at each frequency and reaches input-to-output quadrature at ω=1/RC (i.e., phase shift is 90°)