Games might be multi-platform, but that doesn't mean they're the same. Namco Bandai is adding extra content and characters to the PS3 version of role-playing-game Tales of Vesperia.
Comparing screens of the various platforms offers insight into hardware power, sure, but comparing ad campaigns shows how game companies spin their sales.
So above, the PS3 ad for the game literally states that its the highest peak in the series for quality and volume. Thank new content for that.
When Microsoft had the game as a timed exclusive, the spin was a little different: The game is on Xbox 360 as evident by the ads below.
The "quality and volume" argument is a valid one for consoles getting timed exclusives later, and one we expect to see more of.