Regrettably, early marketing materials for Smart Home Monitor used the term “mode” for armed status, even though Mode already had a completely different meaning within SmartThings. You can still find this in some of the support knowledgebase articles, which is why it’s easy to get confused.
But anytime you see “mode” in a routine or smart app, it refers to the original use of the term, which was for the global status of the location: Home, Away, Night, etc. As in the kitchen motion sensor should trigger the lights to come on if the house is in Night mode.
If it’s referring to the SHM armed status (home, armed stay, armed away) The choices should be limited to those three options, and the field label will probably include “SHM.”