Nintendo has put the Mii characters in many games since they were introduced on the Wii, and now they will be making an appearance in Mario Golf: Super Rush. As customizable avatars, the Miis were used as profiles of sorts on the Wii, and were the player character for the Wii Sports games and other titles like Miitopia on other platforms. Although Miis come in all shapes and sizes, they've become a sort of mascot in their own right, appearing in many Nintendo games, including Mario Kart and Super Smash Bros.
The latest outing for Miis is Mario Golf: Super Rush, in which they will be the main character in the game's new adventure mode. Having a customizable character for the main single player game mode sounds great, especially since there will be stat progression, but a Mii just looks so out of place amongst the Mushroom Kingdom scenery. The Miis don't stick out so much in other games; in Wii Sports they're the only characters and are a major part of the aesthetic, and Mario Kart and Smash Bros. have a kind of patchwork art style because of the large rosters that include many franchises.
Mario Golf, however, has a very typical Mario art style, which leaves the Miis looking inconsistent. They will be playable outside of just the adventure mode too, and will look odd standing next to all the other Super Rush characters. It's unfortunate that customizable characters more in line with the Mario Golf art direction aren't available instead.
Mario Golf Should Have Humans Instead Of Mii Golfers
Mario Golf has had regular human golfers in the past. There were a handful of them in Mario Golf 64, and a couple transferrable into Toadstool Tour from Advance Tour that don't have the odd body proportions of other Mario characters. Super Rush already features Pauline from Super Mario Odyssey, and Peach, Daisy, and Rosalina are all barely stylized.
Standing a Mii golfer right next to Pauline in Super Rush's Speed Golf will only serve to reinforce just how out of place the Miis are in the game. It's ultimately not a huge issue, and will have very little impact on how good Super Rush is, but Nintendo seems adamant about keeping the Miis around and putting them into more and more games even though they typically stick out because of how odd they look. The Miis have a very particular, basic look, and it certainly does not mesh well with that of Mario Golf: Super Rush.