This phrase refers to something that is hidden or concealed, often in a metaphorical sense.  چیزی که غالباً به معنای استعاری پنهان یا مخفی است. 
پشت پرده، پشت ابر
مثال؛
The truth was hidden behind the veil of secrecy.  
 ...  [مشاهده متن کامل]  
In a discussion about a controversial topic, someone might say, “There’s a lot of misinformation behind the veil. ”
A person talking about personal struggles might mention, “I’m trying to uncover what’s behind the veil of my own emotions. ”