this could mean nothing but upon my reread of Superman: Last Son of Krypton i noticed how important physical contact, specifically hand holding, is to chris' character. one of the first major bonding moments between clark and chris is when clark tucks him into bed, and chris asks him not to leave.
there are key moments in the story when people make the realisation that this 'mysterious kryptonian' is also just a little boy, and i think this is it for clark. lois has a similar moment after the bus falls on chris and she sees him cry.
the next time they hold hands is when jor-el tells clark he has no recollection of the boy, meaning there's a good chance he can't have been from krypton — which should make him more suspicious. clark doesn't seem worried about it, if anything, he seems really sad that the boy, just like him, has landed on earth with no family.
then after lois and clark accept chris as their own and start to integrate chris kent into their lives, all three of them hold hands when entering the daily planet.
now before this i just thought it was a really lovely and sweet way to show how affectionate the kents are, until this cover showed ursa and zod.
it might look like they're holding hands, but it's important to remember they never taught chris how to fly (most likely because they didn't care to, or they didn't want to give him the agency to then try and leave/disobey them). so they're just holding him up in the air. in the later story we see that they literally just drag him around by the hand since they don't expect him to fly with them (also to make sure he doesn't escape).
a great deal different to how clark and lois hold him.
then in the final moments we see clark save chris by grabbing hold of his hand.
i just think it says a lot about how we're supposed to see superman in this situation, especially after the previous moments with zod and chris. obviously in this situation clark would have grabbed whatever part or chris he could to stop him from being sucked up by the portal, but something about it being the boy's hand seems important. especially since it gives way to the very last time they hold hands.
the first time chris held clarks hand, he reached out first and held on, not wanting the other to leave him. the last time, clark is the one desperately trying to hold onto chris as the boy leaves.
again, this could mean nothing. chris is their kid so of course clark and lois hold his hand as all parents do, but it just seems a little more deliberate in this case. to really highlight the life chris had, the one he could of have had, and the one he gave up for others.
