I think it's like this: although Xiao Ming and Xiao Hong met for the first time, they both knew each other's existence before, so they revealed their first impression and previous imagination of each other. Perhaps the implication of what Xiao Ming said to Xiao Qiang is that Xiao Qiang must be kind to Xiao Hong, or else he will take something from Xiao Hong. Xiao Ming should feel like a confidante to Xiao Hong. Please adopt it as the best. thank you