There are two different layouts you can choose from when displaying pieces on your Public Profile, Tile View and Grid View. The default view in Artwork Archive is Tile View.
To choose Grid View, navigate to My Profile on the left-hand menu.
Then, choose Public Settings at the top.
Scroll down to Data Settings and choose Grid View Layout.
Keep in mind that Grid View will have more empty space but will preserve perfect ordering unlike the default Tile View which adjusts the order of pieces based on how they will fit into the layout.
Example of Tile View:
Example of Grid View: