noticed this detail. the pretty link comes out almost immediately upon posting and a bit later it looks like twitter picks it up showing title / exerpt / shortlink. the double posting is recent and not aware that i made any wp changes.
Which Pluginn you are using to send posts from WordPress to Twitter? If your plugin does not shorten the link and send as it is(in your way “pretty link”), then Twitter will shorten it, it will show like something.com/pretty-link/ , but if you check that link by just mouse hover link will be t.co/something
Let us know if that the case, and about the Title and excerpt, its Called Twitter Cards. Probably you use some SEO plugin which did that. I made one plugin called “Twitter Cards Meta” which will let you control Twitter Cards look in better way. take a look if you want to learn more – http://wordpress.org/extend/plugins/twitter-cards-meta/
sorry took so long to get back, forgot about this question. the twitter title and excerpt with short code has always appeared that way since day one. seems normal when talking to others and works for me. i use ‘twitter widget pro’ and twitter feed for wordpress’ for live sidebar twitter’ feed. i don’t use seo plugs. i don’t mind the double post but can’t get the first twitter post to be in shortcode.