Does anyone have an idea what this gold ribbon stuff Is? Or how this look is achieved? It doesn’t look to be painted to me...

it looks like real ribbon to me -- just wound around there

it looks like dress trim -- from a fabric store

Sure, like K8 said, it's just thin ribbon wrapped around 2x while crossing over itself.  The black stripped one is  a wide ribbon.  Look in a fabric dept/store for different types/styles of thin gold ribbons.

I have the gold ribbon and have used it in just this way, exactly as -K8memphis described.  I buy it at Walmart.

This may help?

https://www.cakecentral.com/forum/t/783335/how-do-i-do-this-gold-ribbon-wrap-on-fondant

I knew this image looked familiar!!! This was asked last year, using the same image. lol. It looks painted to me, as there is no raised edges along the sides of the cake that would be there if it was real ribbon? But then again, I am far from a professional so I could very well be wrong! 

https://www.cakecentral.com/forum/t/843990/gold-stripes-real-ribbon-or-what-1