as user15… sugested you may have a mobile specific CSS in your child or parent theme – that is conflicting with the logo, have you tried loading the site from the desktop pc with cross browser plat form site ? http://www.onbile.com/info/tools-for-testing-how-your-site-looks-on-mobile-devices/ and http://www.fingermarketing.com/comparemysite.php tools the let you see how your website looks in mobile ? and please try loading the site in desktop safar browser – www.apple.com/safari/ download it on your pc and try running the site in safari browser. might help you detect problem –
The second thing is apple safari blocks many javascript’s that are safe – but it blocks them it has some unsual behavior to handle java – make sure you are not showing your logo enclosing it with java –
if you define in more details with code and css it will be much better to assist you.