You can choose how the layer blends with the layer below from the pull down menu of [Layer Mode].

"The layer below" means the layer that lies behind the current layer, for example, the layer 0 is below the layer 1.

In the L-panel on the left, the layer [line] at the top is the one that is located behind all the others.

Unlike most other layer capable softwares, in Pixia, the layer at the bottom of the panel is the one that is located on top of all the others.

Normal

Most basic way. One on top of the other.

Overlay

The colors of the layers blend together..

Lighten

It compares the colors of the layers and shows the lighter color.

Darken

It compares the colors of the layers and shows the darker one..

Luminocity

Only the brightness of the current layer blends with the colors of the layer below.

Hue and Saturation

Only hue and saturation information of the current layer blends with the layer below.

High Lighit

Only the high light information of the current layer blends with the layer below.

Layer modes are effects toward the layer below.
If you would like to arrange positions of layers, drag the layer to the position you would like it to move.

Layer1 and Layer0 switched.
Now Layer0 is on top of Layer1, which means objects on Layer1 are displayed behind those on Layer0.

The layer, which is located at the top here, is considered to be BASE LAYER and cannot be deleted.