Hi,
For some time (I do not know exactly when), the summaries do not appear on Twitter.com. This concerns not only my account but all accounts. I do not see them, it’s empty! For my friends too.
I tried with all browsers, but it is the same for all (I’m running OS X 10.9).
Examples :


It works very well on iOS and Android applications. I think this is a bug on Twitter.com
Regards