  The companion to PSR J1622-0315, one of the most compact known redback
millisecond pulsars, shows extremely low irradiation despite its short orbital
period. We model this system to determine the binary parameters, combining
optical observations from NTT in 2017 and NOT in 2022 with the binary modeling
code ICARUS. We find a best-fit neutron star mass of $2.3 \pm
0.4\,\text{M}_\odot $, and a companion mass of $0.15 \pm 0.02\,\text{M}_\odot$.
We detect for the first time low-level irradiation from asymmetry in the minima
as well as a change in the asymmetry of the maxima of its light curves over
five years. Using star spot models, we find better fits than those from
symmetric direct heating models, with consistent orbital parameters. We discuss
an alternative scenario where the changing asymmetry is produced by a variable
intrabinary shock. In summary, we find that PSR J1622-0315 combines low
irradiation with variable light curve asymmetry, and a relatively high neutron
star mass.
