Double Arrow in Grid - Any Reason Why?

[chodges]

Hello:

A client of mine asked why there are two arrows in the grid for a sortable column. And I couldn't come up with a good explanation so maybe you can tell me why.

[Kurounin]

Hi,

The second arrow (black one in the right) appears only on mouse over to show the direction in which you will sort if you click the column header.

[chodges]

Thanks! Makes sense.