It could be a juvinile male. They don't really get noticeable manes until their a few years old I believe. If someone is a lion expert, please correct me if I'm wrong. I'm too lazy to google.
I study animals for fun and yes that is a young male. It's not a cub nor a full adult. Sorta a teenage lion if you will. Females are built sorta.. Differently if you will. If you look at the neck you can see the start of a mane. :)
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