Twitter卡 - 无法获取图像的代理URL

Question

Twitter Card Validator有时会显示twitter的错误：image：src - 无法获取图片的代理网址。

域已获批准，robotx.txt存在于Web根目录中。 Twitterbot成功检索到robots.txt，网页和图片，但图片未显示在Twitter卡中。

来源页面：http://www.bluefountainmedia.com/blog/how-to-create-great-content-for-your-business-blog/

Twit：https://twitter.com/mstzfort/status/363004775891087361

元标记：

<meta name="twitter:card" content="summary">
<meta name="twitter:site" content="@BFMWeb">
<meta name="twitter:url" content="http://www.bluefountainmedia.com/blog/how-to-create-great-content-for-your-business-blog/" />
<meta name="twitter:title" content="How to Create Great Content for your Business Blog">
<meta name="twitter:description" content="In case you hadn&#8217;t already noticed, 2013 is all about content. Check out 7 content Ideas (+1 bonus) to help come up with great content for your business blog.">
<meta name="twitter:image:src" content="http://www.bluefountainmedia.com/blog/wp-content/uploads/2013/06/Business-Blog-Content-197x110.jpg">

那么，问题是 - 如何在推特卡中显示图像？