Since Sanae is originally from the outside world, some fans draw her in a schoolgirl uniform.
Sanae's appearance in SA was unexpected by many. Due to that, the fact that she says "You can't worry about common sense in Gensokyo, right?", and her "Miracle Fruit" spell card sounding cute and girly while all of her other spell cards from MoF sound much more stoic has earned her the nickname of フルーツ（笑）(Fruit (lol)), based off the スイーツ（笑）(Sweets (lol)) label, referring to airheaded girls who follow fads without really understanding them. In other words, Sanae is seen as kind of a ditz.
Also since the release of UFO and Hisoutensoku, Sanae's popular image has shifted from soft spoken and demure to markedly eccentric with her knowledge of robots, anime and enthusiasm for aliens.
Sanae's new-found aggressiveness towards youkai, particularly Kogasa, has earned her another nickname among Japanese fans, 絶対許早苗 (Zettai Yuru-Sanae), a pun off of 絶対許さない (Zettai Yurusanai, or absolutely unforgiving). This is usually combined with a picture of her smug expression from UFO against a yellow-and-red-striped background, which is a parody of a famous meme of Futaba Channel, "Maji-resu", a serious reply to a troll/joke post.
Sanae is often shown in fanart as rather large chested, resulting in many things from breast envy from Reimu to sideboob pictures.
Since Sanae's outfit is similar to Reimu's, fans often refer to her as "Player 2 Reimu" or "2P Reimu", a character who, just like in most computer games, will take over Reimu's position if Reimu (as Player 1) is knocked out. With Reimu's red outfit and Sanae's green hair, there are even running gags equating the two shrine maidens with the Mario Brothers.