How does one test the image well?

I’m using XCode 7.3 and have created the CarLot. Everything seems to work except I don’t know what to do with the image well.

With a line in the table selected, I can click the image well and it gets a Blue Border but doesn’t appear to “do anything”. Double clicking doesn’t “do anything” either. It doesn’t seem to be a valid target for drag-n-drop either.

The book says to bind it to Cars, Contoller key: selection, Model key path: onSpecial and to be sure to click Conditionally Sets Editable. This I’ve done. I haven’t seen any thing else regarding the image well.

I was able to copy/paste an image into the image well after clicking in it. (Using the Edit Paste menu item)

Seems like my original issue was an issue with Photos. I can drag and drop from finder into CarLot app. Just can’t drag and drop from Photos.