If I include an url in some applications, for example in a conversation thread in Facebook Messenger
(www.messenger.com), the application is able to show a "key" image from that web site. Is there a special Html tag or attribute that allows the web author to specify which should be the image that is to be shown?
Example, pasting http://www.digitaltrends.com/cool-tech/spencer-the-airport-robot-will-help-you-catch-your-flight/ in Messenger
will display: