1) She was in a good position now, with time on her side.
2) The painting was reframed and hung on the wall, more stunning than ever.
3) The painting was reframed and hung on the wall, a stunning work of art.
You can place a coordinating conjunction in these. Sometimes you may see them with a conjunction, not sure about 3). But not all of these types of phrases work like that.
I just wondered what the difference was if any.
I am not sure what your question is asking, because there is no different use of any conjunctions between the three sentences. "With" is a preposition rather than a conjunction. Also, the second example has neither a conjunction nor a preposition. The construction in all three sentences is very similar, except that the first sentence uses a prepositional phrase.
As as side note, the phrases in the second and third sentence grammatically apply to the noun "wall", although you surely intend to refer to the painting. It sounds like you are saying that the wall is more stunning than ever and a stunning work of art. Read about misplaced modifiers for more information.
