It's a button. You press it.
Tap and hold the button to press it. Release it to stop pressing it. Don't ask.
Credits:
@TricksterGuy : for using several resources from your template, such as audio.wav, AppInfo, and template.rsf
@xerpi : for SF2D and SFIL, both of which were used to create this, as well as for your Makefile
@WinterMute, @fincs : for the 3DS application template, which was also used to create this
@B_E_P_I_S_M_A_N : for the base source code for this application