The site is a single page javascript application and so we are redirecting bots to a JSP page. The meta data on this page is as follows:
The page is generated on the server and we have a bot redirect in place.
This is the metadata we are using:
<meta name="twitter:card" content="summary_large_image" />
<meta name="twitter:site" content="@yovivoapp" />
<meta name="twitter:title" content="some title" />
<meta name="twitter:description" content="some content" />
<meta name="twitter:image:src" content="https://apis.yovivo.it:443/someimage.png" />
<meta name="twitter:image:width" content="480" />
<meta name="twitter:image:height" content="480" />