Apparently it is a "disc" shape, about 12" to 14" in diameter, around 8" deep (thick), likely to be mounted about 48" above the ground level.
The 8" depth is probably so one can conveniently coil the "e-hose" (cord) around (over) the unit without kinking (and to make it look like you are getting something for your money?).
There are some preliminary pictures and "technical" specs in a pdf at http://www.AVinc.com
but they are all subject to change.
I do not know if the Nissan-branded unit is different. Probably, it will not be much different.
The model at AV has several options available, so it is probably more complex (and expensive) than really necessary.
See SOC/GID-Meter and CAN-Do Info
2010 Prius, now for sale
2011 LEAF, sold in 2015
2018 Tesla Model 3
2014 Tesla S, Model 3 in 2019
Solar PV: 33 x 225W -> 7 kW max AC
To Sell: X-treme 5000Li EV motorcycle