I'm shaking my head at KFC's new optical illusion billboard

KFC Hong Kong has launched a new ad campaign that's got us shaking our heads – for good reason. The new billboard features a large-scale optical illusion that celebrates the fast food chain's new Fing Fing Cajun spiced fries in a head-turning display that's equal parts interactive as it is headache-inducing.

Launched throughout the city, the billboards invite passersby to solve the op-art by turning their heads from side to side, resulting in a downright silly interactive campaign that embraces the playful nature of its latest product. (If you're after more mind-bending op-art, check out our collection of must-see optical illusions).

We've seen quite a few optical illusions like this one that incorporate a hidden message within the lines (like this optical illusion that's a designer's nightmare), so what exactly does this one say? Before we give you the grand reveal, take a look and see if you can solve it. 

Drumroll...after you've dizzied yourself trying to crack the code, an image of fries bursting from a box should appear, alongside text that reads "FING FING" (of course, we probably could've guessed). The fast food chain's latest fries-based product comes complete with a sachet of Cajun seasoning that customers are encouraged to shake over their fries, creating an interactive and fun way to customise their culinary experience. Hence the name Fing Fing – meaning 'shake' in Cantonese.

The billboard playfully intertwines the product name with the ad's interactive element, creating a visually engaging and mentally perplexing puzzle that's accessible to a range of audiences. While Edelman's regional executive director, John Koay told Little Black Book that the design process went through a number of phases, including AR augmentation or lenticulars, the simplest form seemed the most fun and attention-grabbing for audiences. 

As well as the obvious nod to the interactivity of the product, the optical illusion's physical element aims to create a sense of fun, "It interrupts people as they’re navigating the hustle and bustle of the city and delivers the message in a light-hearted, slightly silly and engaging way – which connects with the fun interactive attribute of the product," Koay states.

Conceptually it's all a bit silly, but passersby seemed to be getting on board with the mind-bending, head-shaking campaign, as seen in the video below. 

While I definitely need a screen break after trying to work that out, it's really great to see big brands embracing interactive billboard advertising that makes you work a little for the result. You heard it here first marketing teams – more op-art, please.

If you're after more brain-melting illusions, check out this amazing afterimage Barbie optical illusion, or feast your eyes on Müller's op-art campaign that delivers a dollop of '90s nostalgia.