Large display for security reasons and ease of use
2.42-inch OLED 128×64-pixel display.
The BC VAULT display shows all the information regarding specific transaction: Sender address, Wallet name, Recipient address, Amount, and Fee.
The sole purpose of a hardware wallet is in storing private key (for signing transactions) in a secure chip and not directly exposing it, which would deem it susceptible to malware that may be found on connected devices, e.g. computer.
Man in the middle attack (MITM) can be made on the computer, which is why it is crucial to have the possibility to check the details of the transaction that one is about to sign on the hardware wallet.
In comparison: Ledger Nano S V BC VAULT. The size of BC VAULT is a bit larger than the size of a credit card (100 mm x 57 mm x 10 mm).