Method for coupling an artwork to a frame supporting the artwork and intended to be hung or placed on a surface to be shown: - the frame includes an electronic paper, a read only memory storing an identifier of the frame, a circuit board connected to the electronic paper, and a support structure for supporting the electronic paper, the read only memory and the circuit board in the frame; - the artwork is in digital format and is initially stored in a memory accessible to a user of an electronic device by means of an application running in the user electronic device; - the artwork in digital format is associated to a non-fungible token, wherein said user is registered as owner of the artwork in digital format in a smart contract associated to the non-fungible token of the artwork; - the user electronic device is interconnected via radio to the circuit board, receives the identifier of the frame from the circuit board, and requests an update of the smart contract associated to the non-fungible token to register a change of ownership of the artwork in digital format, wherein the change of ownership includes registering the identifier of the frame in the smart contract associated to the non-fungible token as owner of the artwork in digital format; and wherein - as a result of said change of ownership, a display portion of the electronic paper is configured to display the artwork in digital format, wherein the identifier of the frame includes - an identifier of a block chain, - an identifier of a smart contract associated to the frame and - a sequence number released by the smart contract and associated to the frame, wherein the sequence number released by the smart contract associated to the frame is not released to any other frame and wherein the read only memory is programmed in factory to store the identifier of the frame, including the sequence number released by the smart contract associated to the frame, wherein the identifier of the frame is unique, and wherein the change of ownership includes the smart contract associated to the non-fungible token calling a method of the smart contract associated to the frame that associates the ownership of the non-fungible token to the frame. - the frame includes an electronic paper, a read only memory storing an identifier of the frame, a circuit board connected to the electronic paper, and a support structure for supporting the electronic paper, the read only memory and the circuit board in the frame; - the artwork is in digital format and is initially stored in a memory accessible to a user of an electronic device by means of an application running in the user electronic device; - the artwork in digital format is associated to a non-fungible token, wherein said user is registered as owner of the artwork in digital format in a smart contract associated to the non-fungible token of the artwork; - the user electronic device is interconnected via radio to the circuit board, receives the identifier of the frame from the circuit board, and requests an update of the smart contract associated to the non-fungible token to register a change of ownership of the artwork in digital format, wherein the change of ownership includes registering the identifier of the frame in the smart contract associated to the non-fungible token as owner of the artwork in digital format; and wherein - as a result of said change of ownership, a display portion of the electronic paper is configured to display the artwork in digital format, wherein the identifier of the frame includes - an identifier of a block chain, - an identifier of a smart contract associated to the frame and - a sequence number released by the smart contract and associated to the frame, - an identifier of a block chain, - an identifier of a smart contract associated to the frame and - a sequence number released by the smart contract and associated to the frame, wherein the sequence number released by the smart contract associated to the frame is not released to any other frame and wherein the read only memory is programmed in factory to store the identifier of the frame, including the sequence number released by the smart contract associated to the frame, wherein the identifier of the frame is unique, and wherein the change of ownership includes the smart contract associated to the non-fungible token calling a method of the smart contract associated to the frame that associates the ownership of the non-fungible token to the frame.