To add a label, create "Label: <label name>" as an empty object and put one (better) or several objects representing the label inside it. We recommend to having a fixed position outline and the label's text always facing the user. You can use billboards for this.
The Vyzn label is just another 3D object, thus it can have any form.
The label is shown as soon as the user gazes at any object on the same level of hierarchy or inside any of the objects in the same level of hierarchy. You can use colliders for more control.
Here is a video on how to add labels using 3ds Max: