Often times for stuff like festivals, exhibitions and grants, you’ll need to send some sort of image along as part of your proposal. Sometimes we do sexy render stuff but if you already have your vector mock this can be repurposed. I’m a big fan of reusing assets wherever possible.
If you want to take things a little further, you can export your vectors into Photoshop (or similar) and composite them with a real environment. This is one scenario where a 3D render is probably way better if you have the time/resources to get one made.
An initial pitch for the C&G window made with some quick compositing.
In my mural work I’m often dealing with distorted text. Sometimes the idea arrives fully formed but a lot of the time I’m using Illustrator’s effects to help me get there.
If working with a team, these documents can be helpful in communicating the general idea without stifling too much creativity. A fabricator/designer can get a sense of form without feeling trapped by a literal rendition.
I also use these images to help figure out electrical needs, placement etc. with venues.