How difficult would this be to make?

I wanted to know how easy is it to create an app that could take two images and create a new one which combines aspects of the original images.

Just been thinking that it would be cool to have an app or plugin that allows you to "try on" clothes before you buy them.

You could have a saved image of yourself and then while browsing something like Vinted or eBay you see a shirt or dress you like.

The AI could just create an image of what you would look like wearing it.