While Pikachu has appeared in several promotional cards and sets throughout the years, this is, by far, the most unique and rare instance
they're the same card, they just have different artwork
however, unlike the difference between a BGS 10 and a BGS Black Label, theres no significant value difference between an ARS 10 and an ARS 10+
Smothering Tithe has been a point of contention in the Commander community over the past year or so: some players hate to play against it, and others feel its the kind of tool white needed to stay relevant
Once this cream is skimmed off you do start to notice a much bigger trend of the modern/legacy dorks in cube under performing and the standard cards doing much better.
Furthermore, a weighted card, or one thats slightly bigger than the rest, could make it easier to pick out in cases where your opponent gives you a set of face-down cards to pick from