Old Mensa Norway Question 32 - lines above a square

The answer is the bottom left option, but I can't quite figure out why.

Source: This question was on the Mensa Norway IQ Test, but now is on the Mensa Finland IQ Test.

• Has a useful answer been given? If so, please don't forget to $\color{green}{\checkmark \small\text{Accept}}$ it :) – Rubio Aug 8 '19 at 3:19

Rotate the central diamond image $$45^o$$ anti-clockwise so that their edges are now horizontal and vertical.