"Handset mode" UI appears for a split second when joining

[robintown]

Steps to reproduce

1. Join a call from Element Web

Outcome

What did you expect?

I am on a laptop without an earpiece, so I should never see the handset mode UI.

What happened instead?

For a tenth of a second I see the words "Handset mode" and the associated "Back to video" button appear in the middle of the call screen. Then the normal call UI with all the video tiles appears.

Operating system

NixOS 25.05

Browser information

Firefox 142.0.1

URL for webapp

call.element.dev

Will you send logs?

No