Set as Standard, by default, your leaf is already in the viewport when you open up toLeaf.
Alternatively, you can change this to Lobed, which will open up a Lobing tab.
Leaf Type set as Standard.
Leaf Type set as Lobed.
Changes the random variation and distribution of leaves where applicable.
For example, if you have size or twist variation set, changing this Seed value will give you different looks.
Globally adjusts the width of the leaves.
Here the leaf Width is set at 3cm.
Width increased to 25cm.
Adjusts the length of the leaves, again globally.
The Length of the leaves is 45cm, in this image.
Length increased to 145cm, here.