@ Jade Le Maitre
re: display the twitter account of an entry
Sorry, no, it is not.
re: display a screenshot of the website as image
Yes, you want the SiteShot extension.
re: I was wondering wether it was possible to display as an entry image / logo the twitter profile picture ? Or linkedin profile picture ?
You can display the entry logo or image, but, sorry, it is not possible to display the Twitter or LinkedIn profile images.