It's okay, Bar, there's no need to feel self-conscious about it. We still find ourselves trying to put the wrong button in the wrong hole some days, and to be honest, you still look pretty fetching with it undone.
It's an advert, of course – Bar is fully capable of doing up her shirt at all times – for the chaps at Arrow, who make clothes. Clothes like the shirt and tie that Bar has so languorously draped over her figure. Clothes primarily aimed at men.
America's "finest" shirt? Clearly they haven't seen this one
So whacking them on a sexy model like Bar is genius, frankly. We're not the sexiest of men – hey, we're not bad, you know – but seeing pixel-perfect open-shirted swarthy (or curiously hairless) men in ads for clothes, aftershave etc still makes us reach for the consolation ice cream as we stuff our lumpy bodies full of comfort calories.
But we can't ever aspire to be like Bar Refaeli (at least, not without levels of cosmetic surgery that border on nightmare wizardry) so having her wear the clothes in a sort of 'oh hey you're up I was making breakfast and wearing your shirt on account of me being your GIRLFRIEND' way is just, you know, tops.
Full marks all round. More please, Arrow. Maybe Bar could model wearing our shoes to take the bins out when she can't find hers right away, or stealing our coat when it's raining on the way home. Any of those would be fine, as long as she keeps forgetting to do up that shirt.