Your pictures don't have to be upright, you can tilt them either to the left or right and at varying degrees too! You can apply either a left or right tilt to any photo and with either tilt there are three levels of tilt that you can apply.
Tilting can really bring out photos that you want to get extra attention. Try tilting them all to the left and then tilt one that you really want to be noticed to the right! If you right click on a cell you can use the popup menu for Frames and apply the current frame style to all your cells or choose the Random option and assign a random tilt through your poster!
In this example you can see the 3 degrees of tilting in one direction. The greater the tilt the smaller the photo will appear. This is because it has to resize the photo to fit into the assigned space.
When you choose to assign Random tilts to all your photos it uses the Slight variation when tilting a photo. This option is available through the popup menu or the main menu and appears under Photo|Tilt|Apply random tilt to all.