This type of picture is called "trampantojo",  a Spanish name, which means "deception" or "optical illusion". It's the technical term for an artwork that exists since the Ancient World. A work of art is being designed in a way that it imitates reality and leaves the beholder in a state between being amazed, doubting if, up to believing that something artificial is real. A trampantojo plays with the imagination of the beholder offering a surrealistic landscape to dive into...

To achieve a "realistic" look the pictures have been turned upside down by 180 degrees.

To make the deception as perfect as possible,  ideally, the reflection of the trees should be crystal clear (which is a challenge with the omnipresent wind rippling the water) and something surprising, something totally unexpected should appear in the "sky".