Technically, they don't because the second person is not usually referred to an animal. You don't talk to the dog, you talk about the dog. Anyway, it's possible that you talk to the dog (of course you're not expecting a response) as if you were saying "Aren't you a cute little dog?". On the other hand, "Usted" is used for a formal second person, so you would have to use "tú". In that case, you can say:
(Tú) eres un perro bonito.
(Tú) eres un perro lindo.
(Tú) eres tan adorable.
The other ones are almost fine:
¡Qué hermoso cuadro!
¡Qué linda foto! [Picteure is not a word in Spanish]
¡Qué lindo es!
¡Gracias de antemano!