The first click on the wall determines the side of the reveal (sun symbol).
If you want to change you mind before you complete the placement you can press the TAB button and this will swap the reveal to the other side of the wall.
Barry.
One of the forum moderators.
Versions 6.5 to 27
i7-10700 @ 2.9Ghz, 32GB ram, GeForce RTX 2060 (6GB), Windows 10
Lenovo Thinkpad - i7-1270P 2.20 GHz, 32GB RAM, Nvidia T550, Windows 11