item_display allows you to do some special adjustments to your furniture model using the display_transformation property.
You can resize it, rotate it and move it freely.
This feature uses the native item_display feature of Minecraft, you can read more here and online.
You can also use this tool to preview your changes.
This type of furniture entity is useful when you want to create chairs, plants, columns, lamps and similar environment decorations which don't need to rotate based on the surface on which you place them.
This type of furniture entity is useful when you want to make the furniture rotate based on the surface on which you place it.
For example if you have a decorative lamp you can make it placeable on walls, ceiling and ground and and make it oriented automatically based on the surface inclination.