I might be alone here, but imo Shaq was trying to do something similar to Kobe's tweet challenges. He just did it in a macho/tough love/awkward way, and on live TV. But I think he was romanticizing and thinking he could say that and then Donovan would take it personally or say "challenge accepted" and then go crazy and then Shaq would feel like he was on the same shit Kobe was on in terms of mentoring/inspiring the new generations.

All speculation, but I think maybe this was a step away from his hating and petty past, and an attempt to start being more of a tough love older brother/mentor. I think maybe Kobe's death brought about thoughts of Shaqs own legacy, and/or he feels like he should carry on with that energy Kobe had for the yourh.

Again, all speculation but I think thats what was going on.