Specific optional equipment that was standard on the 1977 Esprit is as follows:
The first seven items on this list are always on Skybirds, Redbirds, and Yellowbirds, because they were standard on the underlying Esprit. The last three items, however, are not on these cars because they were replaced with special features. The rocker panel molding was left off because it would have looked bad with the lower accent paint.
This list doesn't include an engine upgrade. In the early 70's, The base Esprit engine was usually a 2-barrel 350 (one engine up from the base Firebird's standard 6-cylinder). This was no longer the case by 1977, when the Buick V-6 became the base engine for Firebirds and Esprits. Engine choices on the Esprit varied a lot over the years, but they never reached up into Trans Am territory, always stopping an engine or two from the top.
This brochure photo was published in John Gunnell's "Firebird Buyer's Guide" with a mistaken caption wondering why it didn't look more like a Skybird. It's not a Skybird.