The developer menu that Nintendo uses to test the internal hardware of the Nintendo Switch was accidentally shown in a Portugese Nintendo Switch commercial earlier today.
The new commercial clearly shows the developer menu running on the Nintendo Switch. In the video the console even displays the firmware version "NintendoSDK Firmware for NX 0.2-0.3".
Throughout the commercial several parts of the developer menu are shown, including a screen that features tabs for several functions used to test save data, controllers, accounts, device, network, sound, time, debug and firmware.
Whether the commercial was actually aired on Portugese television with the developer menu still visible is currently unknown.
In the past Nintendo has confirmed that it often uses post-processing to paste gameplay footage on top of existing stock footage of Nintendo Switch test devices. It seems that in this case that the company forgot to add the gameplay footage.
Nintendo has not yet commented on the video but did confirm that it is targetting YouTube accounts that either upload the commercial or that upload videos that contain captures of the developer menu.