I'm adding responsive styles for our website built in Plone 4 CMS and testing on an old iPod 2 device. When viewing on this device, the logo.png does not display. Plone.org top left logo has similar problem and does not appear on this device. Other Plone websites tested have logos appearing.
I've changed the logo to a different format, i.e. logo.gif, and logo.jpg in the 'base_properties.props' file with no improved results. I was careful to ensure spelling of logo files was accurate.
Many Thanks
It's explicitly removed in the mobile.css file:
#portal-logo {
display: none;
}