This small wood and iron box appears to be empty when opened, but an attuned character may speak a command word to summon an illusory effect from the table below.   

Physical manifestations of the illusion (i.e. the wind, sound, and tactile feeling created) are similar to that of a thaumaturgy spell but can cause no physical harm.  Those observing the illusion who succeed a DC 15 WIS saving throw can tell that this effect is an illusion.  The illusion lasts for up to 1 hour, or until the attuned character closes the box. 

Once the coffer starts producing an illusion, it can't produce a different one, or more of one that has reached its maximum, until after a long rest.  

Notes: Warlock, Wizard, Sorcerer, Druid or Bard, Utility