Sort of the difference between a wall that keeps you in versus a wall that keeps unwelcome people out. But then again, some people believe that the us-mexico border wall is morally equivalent to the Berlin Wall, so who knows how that argument will go.
I don't know, but it is clear that the Chinese firewall is about preventing Chinese people from accessing the wider internet, not about preventing non-chinese people from accessing the Chinese internet.
> the Chinese firewall is about preventing Chinese people from accessing the wider internet
It's not, really. Most of the "wider Internet" is accessible, only specific (mostly US or politically-oriented) properties are inaccessible. Very much like what is being planned in the US.