Putting Pressure on Language

I was attending the dissertation defense of one of my friends who happens to be a poetry scholar. During her defense, she said something that intrigued me a lot. According to her, she likes poems which put pressure on language. I have been thinking about it ever since, and I think I agree. I like poems which not only put pressure on language, but puts pressure on language in such a way that it forces the readers to re-think the inter-relationships between literary conventions, language and social history.