Well, without more context, it's difficult to be precise. However, in the general context of Jesus's ministry, he often showed great compassion towards children. So perhaps in this story, if it's a legitimate religious account, it could be about how Jesus brought some kind of spiritual comfort or miracle related to a dead child. Maybe he showed his power over death, similar to his resurrection of Lazarus, but in the context of a child. This could be used to illustrate his divinity and his role as a savior.
I'm not entirely sure which specific 'Jesus dead child friend story' you are referring to. There could be many stories in religious or apocryphal texts related to Jesus and children. It might be about an event where Jesus interacted with a child who had passed away or something related to the concept of life, death, and Jesus's teachings.