One of the cool things about twitter is that you don't need headlines, thumbnails, or previews. A tweet is one complete thought. If you're going to arbitrarily

One of the cool things about twitter is that you don't need headlines, thumbnails, or previews. A tweet is one complete thought. If you're going to arbitrarily restrict the images to a small size, it doesn't make sense to then use a slightly smaller size as a preview and put each "large" on its own page. If you want to enforce simplicity, make full use of the simplicity.