Questions about making and using Hair Cards

I want to use hair cards for a character, which I think will reduce render time in an animation. I saw a demonstration on AAA Hair on the Blender youtube channel and at the Blender Meetup. I would like to understand the process, but it seems there are some details excluded for the sake of time.
So allow me to present what I have, and perhaps I can get some help filling in the blanks.

Watching the Blender Meetup, I have this shader setup for creating the hair cards, but it seems so dark compared to his.

I expected my result to look similar to this

I’m not sure if it’s render settings I need to change, or a lighting setup I must use, or even if Cycles/Hair or Eevee/Diffuse was used. Please help.

PS. If this is not the right thread for this topic, please direct me to the correct one.