A very Canadian optical illusion

I remember seeing this at a lecture, but I'm not sure which one ...

Thanks Owen, for reminding me about it!


From Owen Anderson's Twitter feed:

Coffee sleeve #opticalillusion! Can you guess which @TimHortons sleeve is bigger? #timmies #WarmWishes #HamOnt
(Actually they're all the same size -- Google 'Jastrow Illusion' for info) pic.twitter.com/IYm9oP0uX1

— Owen Anderson (@OwenTAnderson) November 29, 2017