This is cirno's reaction to first timers playing against cirno on Normal mode. Whether it be Icicle fall: Normal, or her fist non spell, I personally dub: Ice shotgun.
For all the (9) meme, Cirno is actually pretty underhanded on her fight. From what you aptly called shotguns (that spread more if you panic and move too much when dodging) to the entrapping Icicle Fall: Medium to how she shoots and moves (making harder to aim on her), she doesn't feel like a dumb opponent.
Actually, from memory, compared to Cirno, Meiling and Patchouli are actually straightforward: They're more dangerous because a greater mass of faster danmaku, but Cirno seems to be actually trying to mislead and trap you, something you won't see again until Sakuya.