Although such illustrations may fool our visual systems, people are rarely confused about what they see. In the real world, vases do not change into faces as we look at them. Instead, our perceptions are remarkably stable.
Here is just a thought to ponder: even though our perceptions may be "stable," could they also be "wrong?" I am not so much thinking about vases and faces, but about our understanding of our position in the world. We perceive that humans have been placed on Earth to exercise dominion over it. Is it possible that our perception is wrong, and that this perception might actually shift, and make everything different? Could we begin to see our human existence as part of the world of Nature, instead of seeing ourselves as apart from the natural world, and superior to it?
Such a change in perception would either result from and reflect, or actually cause to come into existence, a fundamentally different "reality." In the "real" world, are we in the background, or are we the main event?
That could make a difference, couldn't it?