Use the uploaded image as the base.

Goal: a YouTube thumbnail built to go viral, in 16:9.
Increase: the emotion on the face, the contrast, the visual impact and the focus on the subject.
Lighting: cinematic, with strong separation between subject and background and dramatic depth.
Color: vibrant.
Readability: every element must be easy to see on a phone screen.
Balance: maximum click-through rate while staying professional and realistic.
Finish: ultra-sharp, attention-grabbing, scroll-stopping.