First, the hemisphere rainbow is in the center of Apple's courtyard .. since the event is at Apple HQ ... some HQ reference.
Second, The front edge of the AR googles are far more a hemisphere than the MP 'tube" is.
Apple has again pushed back mass production of its mixed-reality headset and the device may not appear at this year's Worldwide Developers...
www.macrumors.com
Top down view of the headset leaving only the outer profile as to not reveal any details. It is a hemisphere to fit the front of a roundish human face. If there is any LIDAR/range finding sensor on the front even better symbolic fit with the 'waves' in front.
Headset not going into mass production until after WWDC is prefect fine it all getting is a "sneak peak". iPhone didn't go into mass production at the same time it was announced. iPad ... nope. Watch .. nope . Mac Pro 2019 ... nope. Mac Pro 2013 ... nope . Has there been any major new product with a hefty hardware component aspect the required a new OS that was cranking full blast when introduced in last 15 years ... no.
If Apple is going to introduce a new Operating system ... WWDC is the probably the best place to do that at this stage. Already have 5 other ones to cover.
Inventing a match of that invite to the Mac Pro is mainly just trolling for clicks from an audience desperate for information.