So, I'm well aware that Japanese follows an SOV sentence structure. However, I see -very often- the topic appearing at the end of an utterance, rather than at the beginning. For example:
きれいですね、この花は。 This flower is beautiful, isn't it?
I was wondering, why does この花は come at the end here? Is it purely a stylistic choice or is there a grammatical reason for it?
In conversation you hear this often when people want to clarify the topic.
Once a topic is mentioned it is often omitted (high context language).
For example maybe the speaker thought everyone was still thinking/talking about the flower but then realized after he/she said "きれいですね" that they should clarify.
Or maybe they just said it without thinking. Then realizing people were looking their way said ”... このはなは”
Your translation of きれいですね、このはなは could easily have been 'Beautiful flower, isn't it?'
As Japanese sentence structure is fairly malleable so long as the main elements are kept together (mainly that words have their respective particles directly following them to denote their grammatical function), phrases can be manipulated relatively freely, without necessarily changing the meaning.
The order is a stylistic choice.
I am your friend. / Your friend, I am. / A friend is what I am to you.:
（私｛わたし｝は） （君｛きみ｝の） （友達｛ともだち｝) (です）。
（君の） （友達 です）、 （私は）。
（友達） （です）、 （私は） （君の）。
The flower that Taro gave to Maria is red, fragrant, and beautiful. / The flower that Maria is given by Taro is beautiful, red, and fragrant. / Fragrant, red, and beautiful are the flowers Taro gives to Maria.
太郎｛たろう｝さんが / マリアさんに / あげた / 花｛はな｝は / 赤｛あか｝くて / 芳｛かんば｝しくて / きれい / です。
マリアさんに / 太郎さんが / あげた / 花は / きれいで / 赤くて / 芳しい / です。
芳しくて / 赤くて / きれい / です、 / 太郎さんが / マリアさんに / あげた / 花は。
In English as well (but not to the same degree), grammar ‘rules’ are not so much written in stone as they are guidelines for common usage and in some cases can be manipulated, with occasional minor tweaks.
(The whole group) (listened).
(Listened), (the whole group) did.
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(Succinct), (am I not)?
(Am I not) (succinct?)?
Suffice it to say, this is mainly applicable to colloquialisms and care should be taken to avoid too much liberal sentence reorganization in formal/educational settings.
