I requested approval to get an another card (summary_large_image), and then I got a email from twitter.com three days ago saying that “Your Twitter card is ready!”. But cards doesn’t changed new one. Of course I changed meta tags to “summary_large_image” from “summary” on my web site and confirmed validness via Card Validator.
Please check my twitter and site. Twitter: https://twitter.com/kconf/status/335656903097065472 Web: http://t.co/imAALXeJaU
It now began to be displayed properly! Thanks for the support.