Logo Doesn't Show On Tablet

I started to build a site for a client at http://mpearson.ca/
I am now building the real site at https://macinternationalstudentservices.com/

All looks relatively fine on computer but on iPad and iPhone the logo shows as an empty box on https://macinternationalstudentservices.com/

I have gone through all the settings of the first site, which DOES show logo on tablet, and they are exactly the same for the second site which DOES NOT show the logo on tablet or phone.

I have tried a smaller logo, tried both .png and .jpg images, deactivated plugins, removed all custom CSS, increased the width for the logo, decreased width of menu. I can't think of what to try next.

The problem is not just on my iPad and iPhone. It was my brother who told me about the issue, so it's on his iPad too. Can't figure out why it's OK on one site but not on the other when, for all intents and purposes, they are identical.

Would appreciate your help.
Thanks!