used to highlight or convey annoyance or misfortune toward a person or object.
Turn the damn thing off!
Guy:"Damn Daniel !"
The same:"Back at it again with the white vans!"
Damn, in this context means that a guy is about to fucking nut to the photo/video you sent or posted.
However this can be used in other contexts.
*Woman Sends Mirror Pic*
"Damn"