A main screen renders watermarked content. A remote device captures a watermark and extracts a payload comprising a layout type, displays possible answers according to the layout type and receives a response from a user. The remote device captures a further watermark and extracts a payload comprising a correct answer, a ratio value and a token value. If the correct answer is equal to the answer received from the user, the remote device generates a comparison value, compares the comparison value and a ratio value extracted from the payload and, if the comparison between the comparison value and the ratio value indicates that remote device has been selected, displays a message intended to a user. The remote device can further generate a value from at least the token value and display this value as proof of being selected.