Answer
The answer is "Cinderella". Rob's participation in the 2015 film "Cinderella" marked a significant moment in his acting career. In this live-action retelling of the classic fairytale, Rob portrayed the charismatic and charming Prince Kit, capturing the hearts of audiences worldwide. His performance exuded both regal presence and a genuine connection with Cinderella, making him a pivotal character in the film's enchanting narrative.