Here is the clue: “Pay special attention to the items resting on top of the long green counter right in front of the customer.” One object there clearly belongs to a much more modern era. During the 1960s, drinks were commonly served in glass cups, soda-fountain glasses, or glass bottles. The modern disposable plastic water bottle had not yet become part of everyday life.
The answer is the clear plastic water bottle with the blue cap and blue label sitting beside the coffee cup. It is completely out of place in this otherwise authentic-looking 1960s scene. As the original puzzle explains, “That clear plastic bottle with the blue cap and blue label is completely out of place!”
Did you spot the bottle immediately, or did it take you a few seconds? This small detail is what breaks the illusion and reveals the hidden mistake. If you enjoy visual puzzles like this, keep an eye out for more challenges that test your observation and attention to detail.