I have used here "summary_large_image" to keep with the 2015 look.
From what I've seen in the validator :
summary:
image on the left 315x315 if the image aspect ratio is not an square is from its center part
on the right of the image:
title
abstract
URL
summary_large_image | photo:
-Image on the top 600x313
title
abstract
URL
I didn’t test the twitter:site and twitter:creator properties
IDEA : we can use some code similar to :
<meta name="twitter:card" content="[% IF title %]summary[% ELSE %]summary_large_image[% END %]" />
to change the type of card depending on the page and also change image content to the author picture when sending the talk URL, or the sponsor banner, ...
I have used here "summary_large_image" to keep with the 2015 look. From what I've seen in the validator :
summary:
I didn’t test the twitter:site and twitter:creator properties
IDEA : we can use some code similar to :
<meta name="twitter:card" content="[% IF title %]summary[% ELSE %]summary_large_image[% END %]" />to change the type of card depending on the page and also change image content to the author picture when sending the talk URL, or the sponsor banner, ...