Richard Alpert works on a ship in a bottle, Locke returns to lead the others

In 2007, the others have set up camp on the beach. We see Richard Alpert under a tent/canopy working on a ship in a bottle that looks similar to the Black Rock (see the photos of the Black Rock painting here, but it does look similar to the photo from the Lost Experience here).

An other named Vanessa runs over and tells Richard "he's here." Richard gets up and sees John Locke walking into camp with a dead board on his back. Locke says "I brought dinner." Richard seems stunned and says to Locke "It's been three years" and then asks what happened. Locke tells him that he'll explain on the way and says they have an errand to run and they don't have a lot of time. Richard is staring at Locke and Locke asks "What's wrong?" Richard says "There's something different about you." Locke leans in and says "I have a purpose now." Sun and Ben then walk into the camp and Richard asks what Ben is doing here. Locke says "He helped me get back."

Sun asks Ben why Locke said that these are his people. Ben says that Locke became the leader after he left the island. Sun asks Ben who Locke is talking to. Ben says that it is Richard Alpert who acts as an "adviser" and that he's had that job for a "very, very long time." Sun grabs the Dharma recruit picture and runs towards Richard and Locke. Ben seems concerned that Sun is approaching Richard and he calls her name.

Sun asks Richard if he was here in 1977. She shows him the picture and asks again if he was there and if he remembers any of them. Richard says that he was here thirty years ago and he clearly remembers meeting them because he watched them all die.

So there is something different about Locke and I think we can trust Richard's instinct when he points it out. What did Locke's resurrection change in him or is he not truly alive? Was Ben right we he said "Dead is dead?"