How does emjambment and additional syllable in poems construct meaning?

[abbyroselou]

1. Why do poets use emjambment (apart from conforming the rhyming scheme)? What meaning can it be constructed through emjambment?
For example: a poem by Elizabeth Barrett Browning- Consolation
Lines 1, 2 are run-on lines.

ALL are not taken; there are left behind
Living Belovèds, tender looks to bring
And make the daylight still a happy thing,
And tender voices, to make soft the wind:


2. I've seen in some poems there is one extra syllable added to the last feet in one particular line, is it a way to emphasizing something?

[khashan]

Talking of enjambment reminded me of an Arabic poem where enjambment prevailed . It seems exceptionally nice because it played the role of the binding mortar between the lines of a monolithic sensitive story.

I deliberately used ( she ) for the pigeon to transfer the Arabic atmosphere where that pigeon played the main role.
**
As if my heart when they said
Layla from the town has fled
A pigeon whose wing was caught by a trap on a tree
Struggling all night to set it free
Thinking of her two chickens in the wilderness
Where wind was blowing their nest in a mess
When they heard the wind whistling
Assuming mother came back, to meet her they kept wrestling
Neither she succeeded all that night
Nor in the morning she could achieve a flight
**

Needless to say that the outcome of my effort to achieve rhythm and rhyme is humble.
By I tried to put it in an near as I could to an English verse form .
I hope you like it.

[YesNo]

There's a lot of sorrow for that pigeon trapped and unable to get home, khashan.

I think enjambment and extra syllables help to make the poem have a pleasant sound rather than add any particular meaning, but I might be misunderstanding the question, abbyroselou.