Opengraph is an enhancement designed to be visible on compatible terminals.

Each map link corresponds to an OpenGraph tag under a standard that we respect, but each tool has its own policy concerning it. Some SMS software asks you to validate an option, while others only display it on Wifi, and ask you to click to load the image on the mobile network (to reduce data consumption).

Others only display them when your contact is already in the phone, to combat spam.

Finally, some phones or versions of phone OS are simply not compatible with OpenGraph and therefore do not display the tag or thumbnail in the SMS.

What is OpenGraph : OpenGraph was launched by Facebook in 2010 but is now owned by the Open Web Foundation. The aim was to allow easier integration between Facebook and other sites by displaying rich graph objects with the same functionality as Facebook objects. This allowed a degree of control over the information that was shared.

The platforms of the main social networks now offer this tag, although Twitter has developed its own for Twitter Cards (but still accepts the Open Graph if necessary). The information is sent via OpenGraph meta tags in the code section of your site.