I got "WARN: Not whitelisted" for my link

[bday_cards]

This it the link https://ats.appsorama.com/app/bday/card/1370610725 .
In the validator I got:
INFO: Page fetched successfully
INFO: 20 metatags were found
WARN: Not whitelisted

Could you help to find a problem? Maybe it’s redirecting that is done by the link.

[andypiper]

You have no <meta name="twitter:card" content="app"> tag, which is required.