Julia Leonard discovered a pair of faux leather trousers from Zara came with an unexpected bonus feature – and a video posted on TikTok demonstrating the noise racked up more than 3.7 million viewsJulia Leonard discovered a pair of faux leather trousers from Zara came with an unexpected bonus feature – and a video posted on TikTok demonstrating the noise racked up more than 3.7 million views