Now that I clicked the link, I find that it’s application is completely unrelated to what I thought it would be.
I rendered it, in my language-mind, as un-"put down"-able… As if to say the person or thing could not be criticized in a negative way.
To my surprise, it meant that the item (or, theoretically, person) was so attention-getting (-capturing?) as to be impossible to let go.
-Tim