Means “Keep It Simple, Student”.

Meaning, you can often use simple equipment. Like when you are lighting and instead of using many flashes, you use just one. On the camera instead of off camera. Like in this recent fun ‘desat’ shot:

Using  simple speedlite bounce-light.

I explain this technique in my workshops, and use it often. Key is to:

• Be in a small room with white walls (a light box)
• Use Flash Compensation (usually of +1 to +2 stops)
• Think “where should the light be coming from” – 45 degrees above from the subject’s head
• Then draw a virtual dotted line from the head in that direction
• And where that hits the ceiling or wall is where you aim your flash.

It really can be that simple.