Hi Christine, 

A thought here would be to make your image a default content type in a document or image library and have the metadata on the image be part of that document's fields. That would be a way to do it with native SharePoint functionality.

If you are wanting to make this a nice experience you could do it slightly differently. Using our new App Studio Custom Content feature, you could preload the app that image so the user selects the image first through the app. They would then mark or edit that image as necessary and save it to their device. Then within the app they would submit a form, and attach the image they just marked up to the form as an attachment. 

  - see this blog for an example of the new custom content feature

Custom content - help reference here

Let me know if this helps.

Eric

This would be my suggestion as well; look into leveraging the App Studio to load your asset and attach it to new requests via the app. This will allow you to manage the asset if it ever changes or new ones get added and need to be used as default attachments as well.

This would require a bit more effort as it is a change to how you are approaching it now, but you gain so much more in the long run as it can be leveraged elsewhere.