And just to add for those that aren't pilots: When they say "reduced airspeed to V2" that doesn't mean reducing engine power, it means pointing the nose higher while thrust remains at the maximum permissable setting. You're loosing speed but climbing faster.

This can happen if you accelerated past V2 (V2+20 is normal) before the engine failure and then after the failure you slow down to V2 to get the best climb angle on a single engine plus some safety margins above stall etc.