How many people here use Mona font or IPAMonaPGothic for viewing S_JIS art as compared to MS PGothic?
Mona-derived fonts have different glyphs for half-width and full-width parentheses. With MS PGothic at 16px, in "(（" both brackets have the same shape but differing widths, while in Mona and related, the half-width bracket has a visually shorter glyph. Some S_JIS art takes the difference between the types of brackets into account (and was probably made by Mona users) while other AA does not (and was probably made by MS PGothic users).

In a hypothetical AA webfont, which variant would you prefer? Or is this a difference that no one alive other than me gives a shit about?