That's got to be an old old web page.
If you look at the face of the hub in that image, you'll see an uplink switch on it too next to port 4. I suspect this would make port 4 the only port usable as an uplink port.
Nowadays all uplink ports are auto-MDIX so an uplink switch is never seen anymore either. Not to mention the fact that on most modern switches you're not restricted to a single uplink port, any port on the switch can be used for an uplink.
I actually have a working 8 port hub sitting in a box somewhere in my office at home. It was the first network device I ever purchased. If memory serves me, I bought it around 1996 and paid about $150 for it..........and if I'm not mistaken, it was only 10 Mbps.....lol
Oh how times have changed!
It matters not how straight the gate,
How charged with punishments the scroll,
I am the master of my fate;
I am the captain of my soul.