For tomographic studies of relativistic nuclear collisions and of the quark-gluon plasma, photons (real and virtual) are unique. They are the only probes than can be both ${\it soft}$ and ${\it penetrating}$. First we report on advances in modelling the hadron dynamics of heavy-ion collisions using a hybrid approach which consists of IP-Glasma, relativistic fluid dynamics, and hadronic cascade components. We briefly discuss the "photon flow puzzle", and then focus on a recent development in the theory of photon emission from a non-equilibrium, strongly interacting medium.