I installed Banzai 7.7 in a developer ORG and started playing. This is awesome and I am excited to get it into production soon!
I created header and inserted the menu component. I set the item source to manual. I added a couple of menu items including the icons. In the composer all the icons showed up correctly. However after saving the page only the first icon shows up correctly. The rest are set to the green check mark. So I think the icons are defaulting to the green check mark once it goes live. Here are the two comparison images.
In Composer:
!(https://us.v-cdn.net/6032350/uploads/attachments/RackMultipart20150910-6238-1po5uno-ScreenClip 4 inline.png “Image https//d2r1vs3d9006apcloudfrontnet/s3_images/1274605/RackMultipart20150910-6238-1po5uno-ScreenClip__4__inlinepng1441922365”)
In real life .
!(https://us.v-cdn.net/6032350/uploads/attachments/RackMultipart20150910-29348-5y45nz-ScreenClip 3 inline.png “Image https//d2r1vs3d9006apcloudfrontnet/s3_images/1274603/RackMultipart20150910-29348-5y45nz-ScreenClip__3__inlinepng1441922213”)