It still says "effective monthly cost" versus straight up "monthly cost".
Even read in the most naive light, this still more straight forward than the typical auto dealer tactics which are both more numerous and more deliberately designed to confuse.
Take the typical ad for a lease of $169 a month. That could actually use an "effective monthly cost" price next to it. Once you add in the $2400 due at signing (ignoring TT&L), it's really $369 a month and much less of a bargain.
Cell phones could use an effective cost instead of a their, "iphone for $99*" which just aren't the actual cost.
That the effective monthly cost of a Tesla goes down due to subsidies, reduce fuel usage, and maintenance may seem strange, but is very real.