What happens if this device is lost or stops working due to malfunction? All BTC is lost?
What do you mean with
'this device'? Which device? This discussion isn't about one particular hardware wallet nor does it matter. Bitcoins only exist digitally on the blockchain. They are not in your hardware wallet, mobile phone, exchange, or elsewhere. The keys to transfer your coins are found in hardware/software/web wallets.
Besides, this isn't the place to discuss such matters so let's return to the topic of showing pictures of our hardware wallets and the state they are in.