When I purchased my red seat covers (Check post history for pics), I had to specify for EX because the EX has a 60/40 split folding rear seat design whereas the LX seat folds over all at once. Also the hybrid has the battery under the seats but I did not find this to be a problem at all when I ordered seat covers designed for the regular EX.
Possibly, but I like TXAccord's thoughts better. My Touring Hybrid also has the 60/40 split rear seating and that would certainly require a different seat cover than a solid, folding seat back. I don't have any seat covers on my car's seats, so I can't know more than this, and I did not consider or look at any LX models when I bought my car.