No, it's not just an ordinary hamburger, it's a mini foie gras hamburger served in Le Bibent restaurant in Toulouse. As for a mini hamburger it's quite tall and very tasty. One of the many amazing dishes in that restaurant.
Sweetbreads, liver etc.! :-) Yummy!
And lovely local red wine.
As i said resistance is futile when it comes to food in France, do not go there if you are on a diet or are squeamish about eating unusual things. Both, Le Bibent and Le Capoul are fantastic, highly recommended if you are visiting Toulouse.