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 on 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 on 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.
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.
"Sanae is a good girl" has surfaced as a meme, in the English speaking community, as a result of page 29 from one of Happy Flame Time's comics, entitled Cold Wind but Warm Winter.
Some of her dialog in Undefined Fantastic Object has caused fans to depict her as being extremely enthusiastic about youkai extermination.
Some Western Touhou fans have noticed that when Sanae moves horizontally in UFO, her pose resembles Superman.
This could also link to her knowledge of anime and outside world features that Gensokyo doesn't have.
Due to her appearance and star shaped attacks, fans often compare her to Mima.
In some fanworks, Sanae's snake accessory is portrayed as a living creature, sometimes changing its expression with her emotions.