Click and drag on the handle in front of each layer to move them up and down.
Double-click on a layer to rename it.
Variant layer and Fixed layer
Variant Layer (Variant Element) is the element you want to experiment with more variants in your test. When you set a layer to variant layer, It turns to a placeholder that allows you to add more variants later in variant mode. A common variant layer can be a product shot, a background picture, a headline, etc.
Fixed Layer(Fixed Element) is the element only use for decorating the design and you don't want to test more variants of it. Like a decorating graphic element can be a fixed layer.
To set a layer to a variant or fixed layer, click on the " test-tube" or "pin" icon at the end of each layer to switch.
All the artboards in an experiment will contain the same variant layers but different fixed layers to make sure the test data is accurate.