...That's a BLITZBALL in the background.
Literally the Blitzball from FFX.
This is in FFVII: Ever Crisis.
Kitase going all in on the "Nojima really did link X's Spira with VII's Gaia, the Shinra kid in X-2 is *the* founder of Shinra, Inc."
To be clear, this also isn't to say FFVII's "The Planet" is (was?) Spira. No. But in the X-2 Ultimania(?), it's heavily implied by Nojima that Shinra (the young boy) *leaves Spira*, and settles a colony on another planet, intending on mining its resources...
What that implies most of all is that the worlds the Final Fantasy games are set on, at least somewhat, are within the same solar system, or possibly universe.
…Wait. Materia are crystallised Mako SPHERES.
Mako is the energy siphoned from the Planet’s (VII’s) Lifestream (memories/spirits of the dead).
Spheres in X/X-2 were visual recordings (memories).
Shinra (the kid) was a member of the Gullwings, a group of sphere hunters.