What does the phrase "image of language" mean? What purpose does the comparison of the railway station with the image of language serve?This...

The phrase "image of language", from the poem "Railway
Station" by Rabindranath Tagore, helps to identify the way which Tagore "sees"
language.

For Tagore, language is like a railway train. The
train, like language, is "full of subtlety of rhythm" (like the train's rhythm on the
tracks). Words, sometimes, flash by like the "untranslatable delicacies of colour" which
one regards when on a train moving at high speeds.

Words,
as elevated as the ones Tagore used, sometimes "appear as much the growth of the common
soil as the grass and the rushes." The image of the language is both common, as the
soil, and complex, as the delicately intertwined language of
Tagore.

The train, like language, moves things (words) from
place to place. Sometimes with thought and contemplation, other times without (in the
same way people cram onto the train cars).