In this poem, the speaker is making plans for a change in life location and style. S/he has had enough of living in the midst of traffic and the noise and bustle of life in close proximity with other people. It is time to get away and to simplify.
The language and the imagery, as an expression of this desire to simplify, is very expressive but not at all flowery or overdone. There is no lengthy description of the new dwelling; we're just told it will be a "small cabin" made of very basic materials. The plan for food at this new location is also straightforward - nine rows of bean plants and a hive for honey bees. Very simple, very basic, but very adequate - the speaker is conveying the desire for simplicity through images and through the manner in which they are explained.
No need to go on at great length. The speaker expresses the "deep heart's core" need to find a place where the loudest sound is the "lake water lapping with low sounds by the shore." With very simple word pictures, Yeats very effectively communicates the anticipation of the freedom to be found when the speaker arrives at Innisfree.