Looks like there might be two battery pack options? 38 kwh and 56 kwh. Presumably the $27,000 vehicle will be using the 38 kwh battery, and the 279 mile range will be with a 56 kwh battery at a higher price point. The efficiency would work out to 4.98 miles/kwh (279/56). That's impressive if their range methodology is comparable to an EPA range estimate.
https://www.epa.gov/greenvehicles/fuel-economy-and-ev-range-...