Gatwick Airport flights diverted to Stansted after drone 'near miss'

I'm a pilot and can't make sense of 'the plane had to take evasive action to avoid the drone' - I'm skeptical I'd see a drone, unless it were huge, I'm even more skeptical I'd be able to evaluate and take action in time once I did see it. A drone is almost certainly below me in altitude which means it's against the ground as the background. I don't think I have much of a chance of seeing it at all unless it's painted in DayGlo and has strobes. Any else got an idea if you'd see anything in time? I'm flown near geese, they were definitely trying to avoid me, otherwise it wouldn't have ended well. So I've got a sneaky suspicion if I'm on a collision course with a drone, it's going to get hit unless the drone pilot prevents it.