Victoria Beckham found the perfect way to mark Earth Day on Thursday as she shared a snapshot by her eldest son, Brooklyn.While Brooklyn is best known for photographs of fashion and family, he also has an eye for the natural world – as revealed in Victoria's Instagram post.MORE: Brooklyn Beckham's fiancée Nicola Peltz reveals his surprising nickname WATCH: David Beckham gets told off as he interrupts son Cruz's singingThe mum-of-four posted a striking black and white photo showing a lion on the