Sometimes in writing poetry, saying something succinctly, can add to the expression. This might work well for topics that are slightly heavier in tone. For example, if a poet wanted to write about something significant, like a tornado, sometimes a succinct poem can add increased significance to the tone of the poem.
For this poetry form, the form is one line that contains fifteen or less words. The idea, is that using one line with limited words to express something, like a tornado, is a much different expression, than using, for example, twenty lines. The poem will sound different. The idea is that having only one line, only one short way to express something, could, hopefully, add significance to the tone of the expression.