For Alex, when he was in a crate at sea in the first movie. He was probably having unwanted flashbacks to when he was a cub, which we see in the second movie.
Vitaly's dark and troubled backstory of screwing the ring jump by lighting the hoop on fire and coating himself with olive oil. The result is stillextremely disturbing despite the Gory Discretion Shot.
Stefano: He flied to close to the sun and he got burned—literally. The extra virgin olive oil is extra flammable.
Alex's return to the zoo on his podium is this, especially since it's a Dark Reprise of the first film, complete with subdued colours, Alex's frightened expressions and DuBois' auora of evil.