You see, we get a really clear view of the tail end of the car, but there aren't any visual changes aside from the F Sport badge. Since the normal LS 500h doesn't have exhaust outlets in the rear bumper, we assume this teaser image is of the traditional gas-powered LS. When comparing images of the two, they share the same taillights, exhaust finishers, diffusers, and chrome trim. There isn't even a spoiler on the trunk to differentiate the car. There's the possibility some of the chrome now has a satin finish, but it's difficult to say for sure from the photo.
We assume that any appearance changes have been restricted to the nose, sides, and wheels, since there just isn't anything new at the back. The F Sport will likely also have some updates to the interior such as different trim and upholstery, and perhaps a new steering wheel and front seats.
Aside from visual changes, the car should have some mechanical tweaks, since Lexus says the LS 500 F Sport will have "the most engaging LS driving experience yet." We expect the primary change is firmer, "sportier" suspension. However, we won't know for sure until the car's official debut on April 12 at the New York show. Stay tuned for the details.