World of Warcraft stick when Warlords of Draenor launched. All the classic races got an updated model, the Draenei got an updated model, and the Blood Elves didn't. The result is that the race is notably older than its contemporaries. That's going to change soon; the updated models for the race are swiftly moving through development, bringing the Horde's magical addicts up to par with the rest of the faction.
As with the other updated models, the differences are subtle but notable. Blood Elf women have slightly wider torsos and a more defined neck, while the men have better anatomy and a more natural stance. There's no precise ETA, but the team is hoping to have these updated models into the game soon, as rigging and animating are currently underway. You can get some idea of what the finished product will look like by checking the preview.