Totally agree that the test is human centric without even noticing that it is.
But from what I've observed the "smell dominates over sight" isn't as strong as it is said to be. Sheep can recognise people though they do it as a whole entity not by faces - so change clothes and you become a bit strange. They can also recognise basic facial expression. Saw all this on Lambing Live - tried to find a link quickly and couldn't. There was an experiment with full size cut out human figures and the sheep preferred the lane with their owner beside it, and preferred the lane next to a smiling owner rather than a scowling owner. I've also seen cats recognise people from over a hundred feet away - wah hey, here comes my person, come trotting over. They do then do the sniff and rub thing, but there is sight recognition first.
That said, ewes do a lot of bottom sniffing on the suckling lamb to make sure it isn't another ewe's lamb getting a free drink.
And another thought - the smell of home. I definitely react with a deep breath on coming home. A few years back I went to an auction room looking at furniture and found I was getting a bit upset and on edge. It finally dawned on me that my parents had entirely furnished their house with old and antique furniture from auctions, and there was an underlying smell resulting from that, that I hadn't smelt since they died and we'd cleared their house and sent the furniture in their house off to auction (well apart from a couple of bits). In the auction room it wasn't exactly an underlying smell, either.
Further thought - the last couple of generations of humans have been trained to suppress smells - lots of cleaning, deoderant, perfume etc - so there may be more in smell than we let ourselves experience. That said, for me when I was a kid my father was the smell of old Spice aftershave, sandalwood talc and gold block tobacco.