Twitter provides a feature called summary card images: if you’ve ever seen a tweet with a rectangular image included, that’s it. We can specify this image via HTML meta tags. Most tweets from the @hashrocketil follow this pattern.
Changing the image is tricky, however, because Twitter caches summary cards for an unknown amount of time (I’ve read one week). Which means past and future Tweets could include an outdated image for a while.
One solution is to use Twitter’s card validator on your site. Running the site it through the validator seems to refresh the cache for your summary cards.Tweet