SVG vector graphics can be used as masks for views. Please note, that the SVG mask can currently only contain one path or combined paths, that will be used as a mask. To add a mask open the view you like to add it to in the product builder. Above the Canvas, click the "Edit mask" button:
A menu will open. To add a mask, click on the image icon.
In this example the used SVG is a svg with two combined paths. Only the intransparent area of your SVG is masked, the rest will be displayed - this applies to all content you have added or that the customer adds within that view.