In this work, we experimentally study the evolution of the diffraction efficiency and birefringence of a holographic polymer dispersed liquid crystal grating. It is shown that the onset of birefringence coincides closely with the moment when TE and TM polarizated probes start to diffract differently. Light scattering, caused by liquid crystal droplets, is also monitored to understand the dynamics of droplet formation and growth. It is shown that the onset of anisotropic scattering and birefringence also occur almost simultaneously.