That’s true, but not complete. Why should this make clouds reflect white? How is it that randomly-directed scattering can preferentially send the light back in the direction it came from?
Let’s look at the process in a little more detail. When light hits a drop, it gets redirected through refraction and scattering – mostly in the forward direction, but after this redirected light hits more drops the randomness of the orientations of the light and the drops washes out all information about the original direction of the incoming light. At this point, the direction of the light is random and unrelated to the direction of the incoming light. It seems paradoxical that this would end up causing the light to leave the cloud in the same direction it came in. The answer is the random walk.
Imagine you’re walking down the sidewalk and you flip a coin. Heads you take a step forward, tails you take a step back. You keep up this process for many flips of a coin. Your position over a thousand steps might look like this: