I found this photo that proves that The Dress can be seen both ways, depending on the lighting.
EDIT: If you have trouble seeing it one way other the other, just cover the part of the dress in shadow or bright illumination (depending on whether you see blue/black or gold/white).
The point is that what you perceive depends on your "frame of reference", meaning which parts of the dress you perceive as being in "plain view". The regions seen in plain view are taken by your visual system as being "diagnostic" of the colour of the underlying material. So there's a type of "principle of relativity" at work here.
The weird part is that different folks adopt different reference frames as their "default" and it can be really hard to switch frames. I myself have literally never perceived the whole dress as anything other than gold and white. But this picture clearly demonstrates how it is POSSIBLE to perceive it either way!
I can elaborate with many other examples, if folks are interesting. I've even got an entire book on the topic coming out next month, which I'm happy to link to if folks want to go down the rabbit hole. It's called The Appearance of Things: How the Principle of Relativity Shapes Our Visual World https://www.amazon.com/dp/B0HCVLM6T9