Added to the bug list, thanks.
Moth3r said:
A related suggestion for future enhancement - it would be nice if the option could be tailored to be more flexible, e.g. "Replace images with links if wider than 600px/larger than 100KB, etc."
This would be possible with images uploaded as attachments (which isn't a feature yet), but not with images on other servers. An image needs to be on the server for the application to get its attributes.