OK, let's try another busy picture.

The picture shows 3 pushrods, a blue, a green, and a red one. They are attached to a round servo wheel.

When the servo wheel moves 20degrees, the blue pushrod is pulled to the left the amount shown by the purple bar.
When the wheel moved that 20 degrees, the red pushrod is pulled the tiny little amount shown by the pink bar.
That shows how the same movement of a servo wheel in a circle can wind up moving pushrods different amounts in a straight line.

Now lets look at how to use that to drive a pushrod one way a lot and pull it the other way just a little, from the same amount of rotation. The amount you get when you move your TX aileron stick full left or full right.

The green pushrod is hooked to the servo wheel as shown. And the servo is sitting at neutral. Your aileron stick is centered in the TX.

You move the stick all the way right, and let's say that moves the servo wheel clockwise about 45degrees. The pushrod moves to the right the amount shown by the big green arrow.
Now you move the stick all the way left, and the servo wheel would move counter-clockwise. The pushrod end moves to the left and down but only moves left the amount shown by the little green arrow.

If the green pushrod had been hooked to an aileron, it would have pulled it a little bit one way, but would have pushed it about 2-3 times as much the other way.