Photo Card appears as Summary Card - why?


#1

We implemented Twitter Photo Cards to our application and finally got reviewed. But we have following issue:

Sometimes it correctly shows the Photo Card: https://twitter.com/MarianSchubert/status/299449294509989888
But sometimes it shows the card as a Summary Card: https://twitter.com/hellishcz/status/299438298127036416

Why is that? How can I fix it?
Thank you for your help.