Six easy rephrasings for a 6-year-old
The snowy owl blends in with the snow because it is so white.
On the snowy ground, the white owl is hard to see.
The white feathers of the snowy owl hide it against the snow.
Because the snow is white, the snowy owl looks easy to miss.
The snowy owl camouflages itself with the white snow.
Its white plumage makes the owl blend into the snowy landscape.