Yes, actually, that probably wasn't a good example. I guess I was trying to think of a scenario where there might be nested resources that are more than 2 levels deep like 3 or 5 levels. For example,
/foos/222/bars/222/wizards/23423/

Perhaps I am thinking about this too hard and it's very unlikely this would happen?

I also have a few other questions...
Q1. Is it better to use plural for the naming convention of these resources, so for example, /users/123/images/452?

Q2. Is it better to build for different ways of capturing this information in the uri? So for example, /users/123/images/452, which returns image 452

or

/images/452

Q3. I am trying to come to grips with how I would model these resources and which models would be returned/used. If someone enters /users/452/images, I imagine an images collection returns and it uses 452 as the ID to get these images? So in effect, it uses the id before images to find the collection vs. /users/452/images/192 that returns a single image model which uses 192 as the id?

Cheers!