When editing a table why do the add/remove row buttons point horizontally while the add/remove columns buttons point vertically?

[Warren Phillips]

 I understand what the picture is, and it is correct, but not at first glance. The arrows in the icon would add more by not being there.

[Warren Phillips]

Not sure I explained it clearly. It is that the arrows within the icon make it appear something is going to happen in that direction when it is in fact just pointing at the new row/column.

For instance 'add row before' looks like it will add a column as it point to the left. The bold new row at the top is ignored at first glance because the arrow takes precedence to the eye.

[Vera Henrichs]

I think they just want to be safe, in case people don't know the difference between rows and columns.