Karen can pinpoint this whole obsession to a specific moment in time: The moment Peter asked her to get a gift basket for his neighbor who was struggling. Getting that gift basket delivered opened her eyes to the joy of giving gifts to others anonymously. She just loves knowing that she helped brighten someone's day or that she gave them something that will make their life better even in a miniscule way.

The one downside to this is that she has to work around the fact that she's an AI without a physical body. Thankfully, she has FRIDAY to help her, along with access to the cameras in the Tower and drones that she can control to help her deliver her gifts.

The first person she gave a gift to was of course her Peter, even though this one took a lot of time and working behind the scenes with FRIDAY. She had noticed that Peter kept breaking his watches through Spider-Manning or just accidentally hitting it against things with more strength than normal and shattering the screen.

It took a bit of thinking on how to solve this, but she eventually decided to approach FRIDAY with the idea of Stark Industries creating a line of watches that was just as durable as their nearly indestructible phones. Her argument was that it was very annoying to break your watch (at least from what she could tell from her research) and that people would be interested in buying a watch that would never break and last much longer. It would also be beneficial because it would be a way for Stark Industries to experiment with making their indestructible products on such a small scale. After a bit more cajoling, FRIDAY gave in and presented the idea to Pepper who then presented the idea to the company and over the course of months the product was designed and released.

Ecstatic, Karen got access to a bank account FRIDAY has control over and immediately bought a watch in Spider-Man red. She then delivered it to Peter's bedroom desk, maneuvering her drones through the always unlocked window and dropping it off with a typed note of "Peter~ This one shouldn't break :D."

She was filled with happiness and satisfaction when the next time Peter got in the suit he excitedly told her about the new Stark Watch someone left for him on his desk ("probably Mister Stark but I don't know for sure") and how much it touched him that whoever left it for him noticed that he likes watches but they always broke on him.

The next person to receive a gift from Karen was Tony. Chatting with FRIDAY and watching through the cameras of Tony's lab revealed that Tony's feet tend to get cold and Karen was determined to help fix this little annoyance. Searching online brought the results of a pair of fuzzy socks covered in mechanic tools for when Tony needs to be mobile and a pair of heated boots for when he can sit down in one place. To deliver these to Tony she enlisted the help of Dum-E who happily delivered them to Tony while he was working in the lab. When asked where they came from, Dum-E just shrugged before cheerfully beeping and rolling away.

Pepper was her next receiver when Karen noticed that she hadn't taken some me-time for a really long time. Working with FRIDAY, they cleared Pepper's schedule for a couple hours and scheduled an appointment at the spa. When that day came and Pepper checked her schedule she stared in confusion for a moment before mentally shrugging and deciding that she was just too tired to remember scheduling an appointment.

If both Karen and FRIDAY were pleased to see Pepper much more relaxed after her appointment nobody needed to know but the two of them.

When Bucky untangled the mess that was his brain to the best of his current abilities (with the help of professionals of course), he quickly found that he didn't really have anything to do besides fall into mild depression. Noticing this problem, Karen once again puzzled out a solution. She bought art supplies, a guitar, and a new laptop with several games already downloaded that she thought Bucky would enjoy. Along with the laptop were usernames and passwords to online sites that taught him drawing and guitar, along with an online schooling website where he could explore and pick classes that interested him. When Bucky came back from a walk he finally got himself to go on to discover all of this in his room, one of the most genuine smiles formed after realizing that someone put forth the effort to get all this for him after realizing the problem that he was facing. Once again Karen was filled with happiness and a sense of satisfaction.

Natasha was the next person that had the opportunity to receive a gift anonymously from Karen. A few weeks ago FRIDAY had mentioned to Karen that she had overheard Natasha mention that her sister Yelena was going to be in town. With her previous knowledge of Natasha enjoying ballet, a little bit of research, and Tony's name thrown around (because FRIDAY said that Tony honestly wouldn't mind), she acquired two tickets to one of the best ballets in town on one of the days she knew Yelena would be in town. When she saw Natasha actually smile when seeing the tickets left on her desk and realizing what day they were for Karen was elated.

The last person (for now) that Karen gave a gift to was Happy. Knowing that Happy is often the driver for Tony and the others, Karen decided to get him something that he could see as he drove. This led to Karen stumbling across quote car charms that Happy can hang up as his fancy strikes him. She got him three that say "Think positive," "You got this," and her favorite, "Choose Happy." She was excited to hear from FRIDAY that Happy loved the car charms and that his favorite was also the "Choose Happy" one (FRIDAY theorized that it was because he needs the reminder and that it also reminds him of his friends that call him Happy).

So really, Karen's new obsession has turned out to be a good thing, especially now that she has roped FRIDAY into her scheming as well. Her goal is to keep her humans happy through little things, and if this is what does it she is more than willing to continue doing what makes everyone, including her, happy.