What's that strange icon?

[derekfountain]

What does the little yellow thing that looks like a scroll do? It seems to switch to RGB mode, reset the curves, then put a pin on the master curve. Odd. It's also impervious to a reset. Odder. If the master channel is turned off when it's clicked, the master channel appears but has a red surround like the red channel. I'm mystified.

[-default]

It's the "I want to preload the curves from last time" icon.

I'd love to eliminate it, but it seems to be necessary for smart filters to work.