I guess you need to look at the current TAM for visual production in general. That's the baseline (so includes visualization studios, agencies, game studios etc). Generally this potentially can help in many labour intensive parts of a creative visual process.

Is that a "large" organization market or not depends on your metric and what the market positioning of the offering is. I would see applications in both specialist content creation tools as well as "stock photos and merch".

In terms of finding stock photos, if you add a better text api that is easier to control this probably can compete with static stock photos in the sense that people can tune their images as much as they like. For example with their corporate merch (Imagine producing a slideset at Acme co. "Please give me an elephant and walrus wearing acme caps".

Ad agencies already love that they can train a model to quickly iterate product shot ideas extremely rapidly.

Then we have "the usual" effect automation has on market demand - automation increases the productivity of a task requiring labour, hence allowing to reduce the cost of a unit of production, which generally increases the demand. I.e. creative stuff will be cheaper to do, you won't replace artists, but suddenly the dude or dudette who spent hours just tweaking stuff has their own art studio at finger tips to command. They can get so much more done much faster.

The tech is not 100% bullet proof yet but at this pace it will be good enough soon (or probably is for several applications if there was just an UX sugaring targeting specific domain workflow).

Built a plugin for Power Point and sell it corporate wide.

Does it actually make anything in the corporate world better to use generated images in slides? When coworkers use stock photos which were presumably made by humans operating actual cameras, I don't think it's clear that their presentation is actually more valuable as a result.

Why does it have to be large organization? Why can't it be many small businesses.

I suspect those applications will come from specializing the model. For example, there's people that have avatar generators or automated ad creatives. A cool application I've been toying with is generating icons.

Train the model with https://lucide.dev/ and ask it to generate a few more?