tails-installer icon missing

in version 3.0~beta4, i’m trying to use the tails-installer. the launcher icon is a specific tails-installer launcher. but when i’m running tails installer, its icon (in the taskbar, when i alt-tab, or in the side dock when i press the pizza key) is just a generic grey rectangle with a fold in the lower-left corner. It should have the launcher’s icon there.

Original created by @dkg on 12508 (Redmine)