Fetching picture from shared link

Nowadays, I am working on a question-answer website. I want to add a new feature to answering section.

When someone answer the question, if they share the link, the script(which I want) automatically should get the picture related with that shared link.

For example,

if I will share this link:

http://ift.tt/1VC5FWR

and post my answer, it should show the description of glass, the picture and maybe some other small information.

How could I do that ? What is the name of this topic in web technologies ?

Note: I'am using wordpress theme.

Thanks in any idea.