Peter, for whatever reason, and unknown to me as to why, the automotive industry is a bit wonky in how they define tires.
[ Add 'and the tire industry' after the auto industry & I have to agree!]
To most people, a symmetric tire would project a mirror image based off the tires rotating centerline. I believe the auto tire folks often call this a directional tire.
[That is (usually but not exclusively) true. See your comment above!]
The tires we deem as asymmetrical on Spyders, i thought the automotive folks considered them symmetrical
[umm, once again, usually but not necessarily...] basing symmetry as the vehicles centerline and not the tires rotating centerline.
that is the case - - sometimes...] In these cases, the tires can be rotated to either the left or right side of the vehicle.
[Yes!]
The true fact in regards to tires is that when a tire is used on a motorcycle, technically based on two rolling wheels on the same centerline tracking, I doubt you will find anything but a true symmetric tire, with mirrored treaded.
[For motorcycle tires, that IS usually the case... there are a few exceptions that aren't necessarily important here or re Spyders.
All that said, when an automotive tire is installed on a motorcycle, the automotive definitions regarding basic tread pattern being symmetric or not are essentially null and void.
[Yeah, I can see what you are saying, not necessarily tho] The obvious gray area are the non centerline tires on a trike, the Spyder included.
[It clearly is a grey area] However, to apply automotive definitions to all tires or only outrigger tires when installed on a motorcycle certainly appears out of context.
[Again, not necessarily....]
Consider how incorrect it could be to apply the terms we use for moto tires against automotive tires.
In my opinion.
[Not only yours!] The easiest way to consider tires for a Spyder, does the tire have a symmetrical tread pattern based on if a mirror is placed on the treads centerline. If there is no mirror image, the tire is asymmetric.
[That is (at least generally) true - more on this later!]
Going further, some asymmetric tires are what I call equal but opposite. Meaning the tread pattern does not mirror, but is equal but opposite angled tread blocks. Theses tires are not normally labeled inner or outer edge.
[That is correct, & very applicable to our discussion & at least some of the confusion seen here in this thread.]
Then we have tires that are asymmetrical based on using the mirror technique, but are not equal but opposite. These tires present essentially two entirely different tread patterns where inner treads blocks differ greatly from outer tread blocks.
[Yes!]
So in regards to answering your photo quiz, you need to stipulate, are you installing the tires on a motorcycle or on a car.
[It's not really essential, but rather than trying to expound on that here, can I suggest that what I put up later might help clarify that?!
].