India, Aug. 23 -- Optical illusions have become a favourite form of visual entertainment on the internet, offering a fascinating mix of intrigue, challenge and fun. A new puzzle shared on Reddit is once again putting viewers' observation skills to the test, challenging them to spot details that are not immediately obvious.

(Also read: Optical illusion: You'll be crowned sharp-eyed champion if you spot the hidden deer)

At first glance, the image looks like a tranquil photograph of a pond. The water is still, reflecting the blue sky above and the red roofs of houses nearby. On one side, a tree stretches its branches gracefully over the water, while reeds and plants line the edge of the pond.

Everything about the frame suggests calmness a...