It is a physical piece that was sent by post to the conference warehouse.
There is proof that the parcel arrived at the warehouse and was dropped off in the lobby.
It probably disappeared inside the warehouse. I have a good contact with the organizer and they have made a real effort to find it. they have searched everything 4 times in the last week, but it is gone.
it's a 52 x52 x 5 cm piece and weighs 4 kilos, so it's hard for me to believe that it's just "gone missing".
I have adjusted the conditions on Geyser today, so all donations for the bounty will go to HRF and Mempool in any case. You can also find pictures there, more here:
https://geyser.fund/project/4thhalvingblockSince the sats for the bounty are collected via Geyser, there is no Bitcoin address, as this works via Lightning.