The answer to this, for some, is simple curiosity that turns into a habit. Certainly you've heard owners say, "My dog is eat anything!". Well, there are some dogs that will sniff and taste just about anything to answer the questions of "What is this?"...."Is this edible?"..."If so, do I like the taste?"
It's hard to imagine that a dog would like the taste of feces, however depending on what foods were digested and expelled, if a dog is actually eating it, there must be an element that they are finding to their liking.
If a Pomeranian does this just one time and is not taught that it is an unacceptable behavior, he or she may then get into a habit of seeking out poop and eating it. An owner must remember that if a behavior is not corrected, a dog will assume that it is tolerated and acceptable.