No image shows in twitter



**Description of issue: Validator says everything is ok, but no image shows in twitter. **

URL affected (must be public):
<meta name=“twitter:site” content="@Plough_French"/>
<meta name=“twitter:card” content=“summary”/>
<meta name=“twitter:image” content=“”/>

[Troubleshooting steps]:
I added extra parameter to the end of the image url on Dec 4. No help.
I asked the server tech if twitterbot is blocked on the cdn, he said no, he can see it in the logs.