I'm no expert on the technology but God I love our battery powered lawn mower. Our lawn, front and back is mostly temporally embarrassed grass (weeds) but keeping it down is critical in Australian snake season. Plan is to get rid of most of it and do the native plants and minimal grass thing.
In the meantime, no fumes, no refueling, the dog isn't scared of the noise, and it works a treat. The batteries and how to recycle them in the future is certainly something to worry about, but in the meantime it's vastly superior to our old stinky, do a rotator cuff turning it on, 2 stroke option.
Having bought 2 in my lifetime so far my approach has always been to say bugger all to the agent. I owe them nothing. If I have questions I ask, if they ask me questions I give them the most limited information possible, obviously being polite. I always kept my cards close to my chest until it was time to lift the auction paddle.
Say very little; it's none of their business. Dress how you normally would.