BBG vs. BBB ssh -X issue, can someone please explain this to me

I’ve set up a nice Debian 7.9 image starting with “latest” 2015-11-12 with all updates as of today.
Got bonescript, mosquitto, and node-red working nicely, and all the other bits and pieces I like are installed.

Can someone please explain to me why if I boot the SD card on my BBG everything works, specifically:

ssh -X debian@
debian@usbbone’s password:
Last login: Thu Nov 12 13:04:27 2015 from wahine.local
debian@beaglebone:~$ lxterminal

pops up a nice lxterminal window on my desktop.

But if I put the SD card into my A5A BBB and do the same thing:

ssh -X debian@
debian@usbbone’s password:
Last login: Fri Dec 25 2015 21:05: 54 from wahine.local
debian@beaglebone:~$ lxterminal

(lxterminal:1350): Gtk-WARNING **: cannot open display: localhost:10.0

Do I have to disable the HDMI on the Beaglebone Black? Is it an A5A issue?

I’ve posted other threads where my A5A seems “flaky” with different 7.x and 8.x images
and Windows 7 vs. Linux (Ubuntu) hosts.

I’m giving the BBG to a friend so he can get started with node-red for a couple of solar power monitoring & greenhouse automation projects he has in mine.
He’s very experienced in electronics and electrical wiring, but has no programming experience, so this seems like a very nice starting point for him.

I’d like to make a suggestion that if is really aiming at “beginners”, bonescript, node-red, and mosquitto should come installed and working out of the box in the “latest” images. What I did still fits nicely in the basic 4GB eMMC of the BBG