No way to set or select a default webcam
For machines with multiple integrated camera devices (e.g. Lenovo Thinkpad X1 Carbon), Gnome does not provide a way to select which one is used globally, or to set a global default. Applications appear to pick the device by lowest lexical order, i.e.
/dev/video0 is taken as the default over
/dev/video1. This can be a headache to work around if your
/dev/video0 device is, say, an IR camera meant for specialized tasks. A settable global default (perhaps mimicking the user experience of selecting an audio device), which was exposed to app developers, would make the use of multiple webcams a much easier experience in Gnome.