Exactly what would these be appropriate for?

I present to you Anne Klein's Shearling Mule: "A so-soft bootie with coveted shearling."


Photo courtesy of neimanmarcus.com

Perhaps this is for the fashionista who can't fathom dressing down to shovel the snow off her sidewalk?

Frankly, if you're over the age of 2, you shouldn't be wearing "booties."