To actually be larger than first thought or to have the ability to hide it well.
Employee #1 Damn, did you see that new HR girl?
Employee #2 Sure did! Saw her bent over the candy bowl, dominating it. She's sneaky big!!!
Employee #1 No way! She looks hot!
Employee #2 Look, there she is now, at the candy bowl again. Check out that backside.
Employee #1 Damn!!! Never noticed it before, she is sneaky big!!!
Employee #2 Id still hit it though!
Employee #1 Not if I was on it first!!!