Amanda humorously questions if there's an unspoken rule that the people around her must be exceptionally tall. This suggests her surprise or frustration at the height of those around her, indicating that tallness is almost a standard among them.
Acheron responds to her remark by stating that Artemis, a significant figure in their world, has a preference for tall Dark-Hunters, implying that height is a desirable trait in that context. His light-hearted comment about "short men need not apply" reinforces the idea that heights play a notable role in their social dynamics.