The following article contains spoilers from Tim Drake: Robin #1, on sale now.
The start of Tim Drake's new series has not only introduced a new part of Gotham City and new costume features, but it also introduced a greater level of danger for the titular hero. Tim Drake: Robin #1 (by Meghan Fitzmartin, Riley Rossmo, Lee Loughridge, Tom Napolitano) ended with Tim receiving a mysterious parcel from what could only be his secret nemesis. It wasn't Robin that received a package though, it was Tim, who found it placed inside his new home.
This isn't just a way for fans to learn that Tim's new enemy knows who he is, but that whoever they are also has access to Tim's place of residence. In essence, as much as the package is meant to let him know that he's dealing with an equally clever opponent, it is also a way to inform him that from here on out, he is not safe in or out of costume.
The package wasn't signed, and it has yet to be revealed what is contained within, but the message on the tag indicates that it was sent from the villain responsible for the strange animal attacks as of late. The message complemented Tim's detective work before calling him "gumshoe" This is an old term for a detective, but not just any kind of detective. It denotes one who is typically undercover or in plain clothes to disguise who they truly are.
It's not just a little pet name to insult Tim, it is also a way of conveying how his enemy knows what Tim's life is like. This throws a wrench into the dynamic of their relationship. Tim was always playing catchup with this foe, reacting to their crimes after they happened, but apparently they were keeping an eye on Tim this whole time as well. Perhaps these attacks were tests, given to Gotham as a whole to find a detective worthy of the name. Unfortunately, Tim seems to have ensured this person's attention is squarely on him.
The fact that this criminal was able to deduce who Tim truly is could mean multiple things. Working it from their clear love for detective stories, it might mean they are smart enough to deduce who Robin truly was behind the mask from a distance. If fans are to assume that this new villain has physical skills in addition to their mental ones, then they may have been silently stalking Robin for weeks now.
Either way is a terrifying prospect because they were either able to figure out one of Gotham's greatest secrets without much effort, or they are talented enough to remain hidden from a member of the Bat-Family. Now Tim must contend with the knowledge that it is not just Robin in danger, but Tim Drake as well. His neighborhood, anyone close to him, is now at constant risk of being hurt or killed. It also puts Tim at a major disadvantage, he still has no idea who his enemy is, he doesn't even have a name, but now his identity has been compromised and he'll need to adapt.