It could be a few things...failing video chipset (do you have the AMD discreet option?), logic board or display. Looking at it, I'm betting on a logic board swap for that. If you have the Iris and M370X combo, it would likely pop on and off as the computer dynamical switched between GPUs. Book an appointment with the Apple Store. They can run a quick MRI and find out what is really happening.
If you're nice and the problem doesn't appear to be user related, I can almost guarantee they will take care of you seeing as you're just a month or two out of warranty. Just be friendly, it gets further in this world than angry agitation. - Former Genius
PS, if you don't like what you hear, try to politely ask to speak to a supervisor to make sure there's nothing they can do to help you.