There's the same looking disc (black) with two versions of the logo. It seems that one enables mesh, the other is just a range extender. White logo = extender. Multi colour = mesh.
The BT logo was recently changed so some stock will have the old logo and some will have the new logo.
See links about the different types of discs available.
Cheers
The white complete home BT extender discs will work with BT Smart hub 2. They will function in the exact same way as they did with the Smart Hub 1. However one of the white extender discs in the network must still be connected to your hub (router) with an ethernet cable. What the white discs will not do is integrate with the wi-fi network created by the Smart Hub 2 (and any tethered black extender discs). So if you intend to use both white and black extender discs there will be two wi-fi networks available as was the case when the white extender discs connected with a Smart Hub 1.