…and the culprit is found. Insulating tape holds the display to the rear case and protects the Lightning connector cable.
With the tape peeled up, we remove the display assembly and can turn our attention to the interior.
Bad news: due to the placement of connectors, you'll need to remove the LCD prior to removing the digitizer. Great news: the LCD and front glass are two separate components. This contrasts the fused glass-LCD assemblies in both the Kindle Fire HD and Nexus 7. Thanks for the repairability, Apple!