Need to change the default easyblog twitter autopost image

Hi,

I'm trying to figure out how to change the default image of for easyblog posts which feed into twitter.

So if I don't have an image on the post when twitter pulls the post the link has a generic grey icon, instead I would like to replace it with my own default image, so if there is no image on the post, twitter will just use the new image instead.

I think it's something to do with twitter cards as per post #189175, however the file structure you have does not appear on my structure.

I've attached an image of the problem.

Regards

Gurps