I'd assume pets are hard as there are so many varieties (potentially even harder than humans). For the last few years Google Photos has correctly returned photos for a search of "Lamborghini" in my albums. I'd expect "shirt stripes" to fall into that category.
Sure, I’m not saying it’s an easy problem — just that the marketing is once again setting the field up for failure by giving the impression of human-level performance but delivering results only in very narrow scenarios.
There’s a nuanced argument that practitioners know how ML is so dependent on training data and accuracy tails off sharply, but that nuance tends to removed from anything selling to potential customers — which has not been a great way to keep them in my experience.