What is a correct term for images that are to act as containers for other content, e.g. for holding text or cropping images?
Common examples of these content-holding images are badges, thought bubbles, stickers, flags, ribbons, starbursts, etc. Here's a couple of examples of more interesting [whatever these are called]:
So we're talking about simple images, typically solid colour / silhouette that are used to contain text or crop/clip photos.
Imagine an organisation had created a library of [whatever these are called] to give commonality to their graphics. What would you call it?
They're not typical illustrations because their role is purely to support another item of content. They're a bit icongraphic in that they represent something in a simple way, but they're not typical icons. I'm sure there's an obvious term I can't think of that is better than "content-holding images"...