What is the meaning of it's all in the surface?

Answer 1

'It's all on the surface' means that something or someone has no hidden depths.

In my opinion this isn't an idiomatic expression, and I would avoid using it. It could be interpreted either as a compliment or as an insult, so there is a danger of being misunderstood.

'It's all on the surface with her' could mean a) 'she is open and straightforward' or b) 'she is shallow'. Better to use an expression that is unambiguous.

Answer 2

"It's all in the surface" implies that superficial appearances or outward impressions are all that matters in a situation, disregarding deeper meanings or underlying truths. It suggests that what is visible on the outside is the most significant aspect.