If a picture is usually worth a thousand words, this one is worth millions.

[BruceWane]

6. Eh, I wouldn't be so quick to doubt it.

You don't have to use a tray. Pro painters usually use a grid that is hung on the inside of the bucket, like this.

And as long as you're not going wild with your roller, you don't need much of a drop cloth when you're painting a wall.

Also, if that was photoshopped, they were pretty meticulous to get the reflection on the floor correct (includes the edges already trimmed in, etc).