Was looking at Psalm 8 today, and thinking about v3-8 - the "what is man...?" bit, and reflecting on how it works.
Here are a few thoughts:
The context is clearly about God's anointed king being rejected by the nations, so it seems more than fair for "son of man" to refer to Christ. It's quoted in Hebrews 2, where it's clearly applied to Jesus, but as an archetype of people. Jesus is made lower than the heavenly beings and then exatled as a result.
But where it got really interesting was in asking how this relates to the mandate given to Adam in Genesis 2. He's told to rule over the animals, birds, fish, etc; this seems to be what Psalm 8 is primarily referring to, except that in Hebrews 2, Psalm 8 is treated as being about Jesus and his exaltation.
I think this shows that Jesus' exaltation and rule is a fulfilment of the mandate given to Adam to rule, and so that Adam's mandate reaches a greater fulfilment in Jesus and then in our exaltation and rule with Christ.