  We study photon production in the early stage of heavy-ion collisions using a
multistage model combining IP-Glasma, K\o{}MP\o{}ST and relativistic
hydrodynamics. We discuss the small momentum anisotropy of these photons,
highlighting the role of the photon-hadron event-plane decorrelation. We
comment that this singular characteristic of early photons could be used to
provide dynamical information on the complex pre-hydrodynamics phase of
heavy-ion collisions.
