sweet pic and Pom's are cute...yes, Poms -can be - difficult to housetrain, as can many small dogs, because they do have such a tiny bladder and also small dogs have a higher metabolism. Many small dogs are also especially prone to be victims of puppy mills simply because they 'sell better' - more appealing to the novice or "spur-of-the-moment" adopter, cheaper to "factory farm" -more to a cage, lighter cages etc. Safer to handle than bigger dogs.
Now - small dogs can and do get house-broken but it often takes longer. Many people with small dogs in condo's or apts. or in the city, "paper-train" and/or have dog litter<like cat litter, but for a dog> and indoor "bathroom" spots that's like a kid's sandbox but with fake turf for example.
Poms are often big barkers. Originally they were sized bigger and were a herding breed, and herders can be "bark-y". They are active and feisty little dogs.