Log Detail window comes up blank

[philrz]

Repro is with Brim commit b87abd5.

As shown in the video below, If test data is loaded into the app (such as sample.zng from the Brim repo), its details are rendered ok in the side Details panel, but if I double click the log line to pop out the details into a separate window, the window comes up blank. DevTools Console shows no error messages.

https://user-images.githubusercontent.com/5934157/176330291-14578a31-aced-460e-8aa8-66374b4d60cd.mp4