Difference between the authors point of view and purpose

Author's point of view is how the story is told in (first,second,third) but purpose is why the author chose to write the article/passage/story.

both the address and the poster use diction to convey their message. diction is defined as a style of writing or speaking based on the types of words chosen in order to send a message. parallelism is when a similar sentence structure is used for several sentences on a text; roosevelt's address doesn't follow that. repetition has to do with repeating a word or sentence in order to emphasize and idea, however neither the poster nor the address use repetion. finally, the address doesn't use images to convey a message.