Although it doesn't say leather seats, the power seats option only comes in the luxury or leather package, so by deduction it has leather. The picture too tells you it has leather since the fabric interior only comes in black, regardless of exterior color.
You may also notice that this guy isn't a Lexus dealer, (and according to the website, they only have one) so anyone who test drove it would be the one buying it, and therefore may not have floored it or peeled out at every opportunity, but rather drive conservatively since it may be their future car.
Taking a brief look at their inventory page will also clue you into the fact that these guys deal with exotic cars, and people at exotic car dealerships don't hand the keys to any Joe Blow with a license if you know what I mean.
So overall, if he set his reserve at below 34k, then it would be a pretty good deal for someone who has to currently wait for IS's to trickle through from their local dealership.
P.S. I don't think he's lying about any of the options, since he has a feedback of 8, and guessing that all he's sold is cars, that's a pretty good track record.