Made a Big Mistake at Work on My First Day

I started my first job last week as an intern at this marketing firm. Everyone seemed nice and the work was interesting enough, but I couldn't shake off the nerves. On Friday morning, my boss asked me to draft up some social media posts for the next campaign. She gave me a list of rules and guidelines, which I glanced over quickly before diving in. I worked all day on these posts, feeling pretty confident about them when they were done. They sounded perfect, witty, and right on brand. When I sent them off to my boss for review, she called me into her office looking more frustrated than happy. 'What's wrong?' I asked, worriedly scanning the emails hoping to spot any glaring mistakes in the drafts before she did. 'Social media is about reaching out to our audience,' she said slowly. 'These posts are... well, they're just not very social.' I blinked several times, still trying to figure out what I had missed when it hit me like a ton of bricks - my guidelines from earlier that morning were the rules for writing formal company emails, not social media. So my posts were too stiff and proper instead of casual and engaging. 'Oh... Oh no...' I muttered. 'That's... I didn't mean to, ' 'It's okay,' she said, though it wasn't really comforting coming from her stern look. She had me delete all the posts before they went live and gave me a pep talk about reading instructions carefully. Now everyone at work calls me 'The Intern' or just 'Intern', even the people I didn’t know when I started. I feel like they think I'm an idiot, but I'll do better next time around. If anything, this has taught me that there's a difference between formal and casual writing styles.