Sarahjo - not really very good for the engine to rev it hard when you're stopped
but no need to worry (it's a tough engine).
The idea of the lights (as Nick said) is to allow you to accelerate hard, letting the engine rev up to maximum, and just at maximum power you get a very quick 1-2-3 of lights that you should see in your peripheral vision telling you to change gear straight away. They need to come on right at the last minute, so you get the flash effect to get your attention.
It's a bit of a marketing ploy (like the starter button) and is echoing the shift lights seen in racing (and F1) cars. On a cooking hatch most people will not thrash it to within an inch of its rev limiter. It is though a lot more useful on the diesel, which runs out of revs earlier (and there is often a benefit in changing before the red line, due to the high torque peak).