Generally speaking, the unity of couplets depends on the writer's brushwork and layout. If the writer can master the brushwork skillfully and arrange the position of each word reasonably in the creation of couplets, then even if the two sides are uneven, they can present a unique aesthetic feeling.
However, if the writer has not reached this level, it is suggested that the couplets be written as neatly as possible. This can not only improve the overall visual effect, but also better show the writer's skill and intention.