[yakubin]

Given that shutter sounds are produced, I'd guess the shutter is opened[1]:

> During this time, shutter sounds will be produced.

[1]: <https://helpguide.sony.net/ilc/2010/v1/en/contents/TP0003229...>

[dghlsakjg]

The shutter is actually being closed. On mirrorless cameras the shutter is by default open so that viewfinder framing can be accomplished, then it quickly closes, opens for the photo, and ends closed before opening again to act as a viewfinder.

In the case of a reference photo it is closing, not opening, taking a read of the sensor, then opening again.