Dropbox folder size includes backed up files

I found the culprit which is a hidden folder which just contains the same files as the ones that need to be backed up. 

But in fact this should be online only, i will try to put it online only and see what that does

I find it a bit strange though because i already have those folders on my harddrive, thats the whole reason for backing them up

So its strange that dropbox in fact copys the whole folders into the dropbox on my harddrive, thats why its counted double