Desmond had Flash's depicting Events that would follow.
As well as the obvious changes there were also some minor changes
That Desmond could not have effected
The reflection in the Helmet changes
Arrow Tail looks older and more tatty
Location has changed slightly & Charlie dose not hold out his arms
The Conversation between Charlie and Hurley about superman
Desmond's Flash
Ooooh vibrations, whatever would superman do if he ever came up against a wall
Actual Event
Ooooh vibrations, and what would superman do if he ever came up against a wall
Also Note Hurley's tone when he says "No smashing allowed"
Desmond's Flash
Perhaps we should fit Superman with a pair of Kryptonite.......What the hell
Actual Event
Perhaps we should fit Superman with a pair of Kryptonite ballet slippers.......What the hell
Personal Note:
These events could not have been effected by Desmond's actions.
IMO the differences suggest Desmond is seeing Flash's of events happening in Other time lines.