What do you see first?
This optical illusion has taken social media by storm despite being created more than 100 years ago.
After its first appearance in a German magazine in 1892, it was used by American psychologist Joseph Jastrow to explain how the brain works.
Apparently, the quicker you can alternate between a duck and a rabbit, the more creative you are.
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This could also be an indicator as to how fast your brain works.
Interestingly, the psychologist also believed that the time of year also determines what you're likely to see. Apparently, if you viewed the image around Easter, you were more likely to see a rabbit. But a duck is more likely later in the year.
Sources: independent.co.uk, news.com.au