"Please send another picture to verify aliveness," another added.
Others made jokes about the scenery.
"Bro! You put that back right now, mister, or you're grounded for a month!" a third wrote.
A fourth added: "That's one smart dog. He's really going to get a head in life! I apologise in advance for my terrible terrible pun. Couldn't resist!"
Someone else noted how this illusion was pulled off and wrote: "I can see it now! His head is resting on the elevated ledge, and his body is behind it. That guy sitting at the top of the ramp makes the perspective even more confusing because he looks to be on the same level as the dog's head."
Dean Jackson, who goes by @beatonthebeeb, put a cyan filter over the traffic lights. And although the colours seem to be muted, our brains and eyes can still identify the colours as amber, red and green, which is the optical illusion.
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