Mining?

[fullback]

when the bar is going left/right etc
when you click on the bar at the RIGHT momement that the bar is moving left/right
then you open it quicker

What a GM said to me.

Is there a trick to mining?
Like, when you click on say, a Copper Ore, there's that little yellow line.
What is the purpose of it?
I tried pressing buttons when the gauge went onto that line, but I see no difference.
Help? =x

I was wondering the same thing about that bar a couple days ago but I figured out what it does and it will open even if you dont click.