:( When you want to give a like under K2 article/item itś possible (great!) but then it gives you an opportunity to put a comment to facebook and in this case the picture goes with it to facebook comment.

I don´t like the picture which goes there still (I used it ones) and I don´t know how to remove it.

When I put item with its own photo or picture then the picture is often ok - a picture goes with his item/article but

when there is an item without picture and you want to give facebook like than you have here still that terrible picture which is put automatically as an ailustratied picture of an item.

Thanks for any advice!

The picture used is the item's image.
Make sure that
a) you use the image tab to upload your image
b) in K2's parameters (image tab) the image size you are using for sharing is at least 200px in both directions.