Because the haiku is shorter than other forms of poetry it naturally has to depend for its effect on the power of suggestion, even more than they do. As haiku are studied further, it will be seen that they usually gain their effect not only by suggesting a mood, but also by giving a clear-cut picture which serves as a starting point for trains of thought and emotion. But, again owing to their shortness, haiku can seldom give the picture in detail. Only the outlines or important parts are drawn, and the rest the reader must fill in for himself. Haiku indeed have a very close resemblance to the "ink sketches" so dear to the hearts of the Japanese.
-- Harold Gould Henderson, Introduction to Haiku: An Anthology of Poems and Poets from Basho to Shiki, p.3
Below is Henderson's haiku, which is quoted from his December 21, 1970 letter to James W. Hackett:
House fronts in stiff rows ---
and all the trees bend from them
toward each other.