If a member is not logged in, as a guest, in my case, running the latest invision board, a message is displayed to create an account. However, i do not see this message here on this community.
Is this a setting that i am missing somewhere or a css trick?

It depends on the permission settings of the specific forum/section. It shows if logging in a regular member would give you permission to comment. If the forum/section needs special permission (e.g. premium/client/moderator permissions), then it won’t show, because logging in won’t give you permission to write and the message would simply be wrong.