There's no completely accurate way to distinguish a 30 kWh pack (which is the only one so far, for warranty claims, that Nissan has replaced with a 40 kWh pack) from a 40 kWh pack, based on photos of the dash alone...
Nominally, a brand new 2017 LEAF (with a 30 kWh pack) would show a GOM estimate of around 105 miles at full charge. A 2018 LEAF with a 40 kWh pack would have a nominal GOM estimate of around 150 miles at full charge. But there are a lot of variables that can mess with those estimates...
For instance, if you had a 2015 LEAF with a 40 kWh pack and the last time the car was driven was up a steep hill, just before the dashboard pic was taken, then based on the GOM estimate you might think it's a 30 kWh pack.
Or, a 2017 LEAF with a very healthy 30 kWh pack, driven lightly on flat terrain just before the dashboard pic was taken, could be mistaken for a 40 kWh pack based on the GOM.
There are lots of other variables...
So, you could guess right most of the time by looking at a pic of the GOM and SOC but it wouldn't be a guarantee.
LeafSpy would be a much better way to determine the pack size, based on the reported GIDs.
Vancouver, CA owner of a 2013 Ocean Blue SV + QC, purchased 01/2017 in WA
Zencar 12/20/24/30A L1/L2 portable EVSE
1-1/4" Curt #11396 hitch
After market, DIY LED DRLs
LeafSpy Pro + Konnwei KW902 ELM327 BT OBDII dongle
Loving my first BEV