Here is what I found online...looks like you've chosen a good excursion. While I didn't find any pictures, hopefully this info will help...
Cruise lines don't own the tour companies—they are independent contractors, chosen based on their reputations for safety and service. Oftentimes, several cruise lines use the same tour operators and, in some instances, individuals can even book tours with them independently.
An example is the "Passion Island Beach Adventure With Lunch" that can be booked when Carnival Cruise Line and Princess Cruises ships are in Cozumel. The following descriptions are taken from their shore excursion brochures:
Princess Cruises: "Have you ever imagined a private, secluded stretch of soft white sand far away from the crowded resorts? If this sounds appealing, then this is your chance to get away from it all and spend a relaxing day in just such a place, Passion Island. After leaving the pier in an air-conditioned bus, you'll pass through town as you head toward Bahia Ciega, on the northwestern coast of Cozumel. To reach your island paradise, you may choose to paddle a 4-person canoe through a calm lagoon or take the motorized transfer boat. After a welcome drink and orientation, you'll have ample time to enjoy the beautiful beach, relax in a hammock, swim, sunbathe, or explore. There are complimentary beach chairs, freshwater showers, a volleyball court, and other fun beach activities. To quench your thirst, a complimentary open bar serving both non-alcoholic and alcoholic beverages is provided, and a delicious Mexican-style buffet lunch will be served during your stay. At the end of your relaxing, fun-filled excursion, you'll be transferred back to the ship." Duration approximately 5 hours; price (2003) $72/per adult & $58/per child.
Carnival Cruise Line: "Escape to a private island beach paradise for a day of fun in the sun. A short ride from the ship takes you to Bahia Ciega pier where you will cross over to Passion Island either by canoe or motorized tender. Enjoy Passion Island's white sand beaches and majestic charm while playing beach volleyball, lying on the beach on an ocean float or swinging in a hammock. A traditional grilled lunch including Mexican fare, chicken and fish, as well as an open bar will be provided for you to enjoy." Duration approximately 5 hours; price (2003) $69/per adult or child.
Reality Check: What did CruiseDiva.com think of Passion Island? We're glad you asked... "We boarded a bus bound for the dock where, after a short boat ride, we would be on Passion Island. Part of a natural preserve, and named for the fact that it was a favorite spot for honeymooners, Passion Island was cut off from the mainland by a hurricane in 1988. That quirk of fate makes it an incredible 'private' island for a day of sun, surf, and serenity."
"Don't plan to spend the day here if you want action. While an excellent Mexican buffet lunch and an open bar are included, a maximum of 600 people enjoy the island and its tranquility—Passion Island isn't a spot to party hardy. There are no paddle boats, jet skis, or parasailing to upset the ecological balance. Passion Island is ideal for relaxation and some recreation. Plenty of great lounge chairs line the beach, thatched huts and palm trees offer shade, hammocks sway in the breeze, and, for more active beach-goers, there are volleyball nets. Noticeably missing are the annoying vendors found on many beaches, although there are nice souvenir stands with good buys on silver and crafts. Bring your own snorkel equipment if you wish as the water is incredibly clear. However, with no reef offshore, the underwater scenery isn't abundant. It's a day of sun, sand, sea, and pure pleasure!"
In short, we loved it. Food was exceptional, the staff was friendly, and it was an idyllic beach day. Worth the cost? We say "yes"—if you are only planning one "beach break" and your cruise itinerary doesn't include a private island, this is as good as it gets... no crowds and an abundance of privacy!