1) While there's nothing magical about the note itself, it does appear to have come from an otherworldly place. If Marina has scanned any of the objects previously recieved in the Velvet Room (e.g. - the prizes given out by Irene after training), she will recognize this as being similar.

2) The note tastes like paper and ink. Don't eat the note, children.

3) If Marina still decides to bully freshmen, she may get detention. :( Let us know based on the first answer!