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cards

#1
<meta name="twitter:card" content="summary_large_image" />
<meta name="twitter:description" content="Come join Gadgeon at Booth #1709" />
<meta name="twitter:title" content="GadgEon - IoT World 2017 | Worlds Largest IoT Event" />
<meta name="twitter:site" content="@gadgeon" />
<meta name="twitter:image" content="https://www.gadgeon.com/iot-event-2017/images/banner.jpg" />

What is the problem with meta tag?