A Samba share is like a network drive. Your browser doesn't normally have to support the protocol explicitly, because it's handled by the OS, & works just like opening an HTML document on your local machine.
@publius I have exactly the same theory in my head.
But in practice, each application in Gnome seems to be supporting SMB. Files, Evince, Rhythmbox, VLC etc. are all individually supporting SMB. If I drag and drop a HTML file into the browser, it simply searches for the file path (smb://path/to/file.html) as a search query.
There doesn't seem to be a way of opening an SMB mount in a terminal.
Assuming that you have "smbclient" & "cifs-utils" installed (which may not be by default), your problem may be that, according to the link below, "By default only root may mount SMB shares on the command line." It's an Ubuntu-oriented page, but the advice appears as though it should be more broadly applicable.
@njoseph
That's messed up.