Notifications
Notifications
[White Hat, Megan and Cueball are standing next to each other. White Hat is separated from the other two figures by a small margin.] White Hat: And another thing that annoys me about people is... Cueball: This user has notifications turned off.
[The camera zooms in on Megan and Cueball. Megan turns to look at Cueball.] Cueball: They will see your messages when they're back. Cueball: Notify anyway?
[The camera zooms outward to show White Hat. Megan turns back to look at White Hat. All three figures are standing silently.]
[Megan turns to look at Cueball again.] Megan: What are you-- Cueball: Shhh- It's working.

Many devices will notify the user when something of possible interest occurs (e.g., a new phone call is received, a load of laundry is done).  Some, such as the instant messaging software Slack , allows you to turn notifications off while you're offline or away (or just don't want to be disturbed). Such a function would be desirable in real life, as illustrated here.  The sender can sometimes override this and notify the user anyway.
White Hat is telling Cueball and Megan about "another thing that annoys [him] about people," which means that either the strip begins after he has already vented a long series of gripes, or he is prone to spontaneously airing one of his many grievances non sequitur .  (Both of those traits could be something that annoys Cueball about people.) Cueball responds by "turning off his notifications" from White Hat. White Hat immediately falls silent, sparing Megan and Cueball from further boring "conversation". Maybe Cueball has picked up the "Commented" trick , White Hat is thrown off by the unusual statement, or it could be that he just naively takes Cueball at his word.  Either way, now that he "knows" that he will not receive any further immediate engagement from Cueball, he thus gives up, for the time being, talking at Megan and Cueball about his annoyance(s). If he believes the premise, he might recite the rest of his conversation as soon as Cueball supposedly turns notifications back on. His behavior is reminiscent of a user who is logged into a chat server but is "away from keyboard" and totally disengaged.
Megan starts to ask Cueball what he's doing, but Cueball shushes her to let it 'keep working' -- presumably, if Megan speaks up, she might alert White Hat that Cueball is still listening and draw him back into conversation.
In the title text, this is taken even further by combining this with a standard real-life reason (or excuse) to leave a social situation: that the person has to leave because it is getting late. It is often used when someone really has a thing early the next day and wants to get home early to get enough sleep to be prepared for the "thing", but the vagueness of the thing suggests that they just want to get out of uncomfortable company or situations.
The specific time, 10:34 pm, informs the messenger (who could be anywhere) of the user's time zone, and tells the one that wishes to notify that it is past the normal bedtime in the user's time zone. And this is why the program would normally ask if they still really wish to notify them, since they would risk waking the recipient up. This could cause annoyance if the message is not urgent and important. In this case, however, it is clear he is awake and wants to leave the social situation, supposedly because of a thing he has the next day. In this situation, it is funny because apparently it's Cueball talking about himself in the third person to another person who knows they are in the same time zone, and unless all of the characters are out really late it's unlikely that it's actually that late at night in "Cueball's time zone" at the moment.
An alternate explanation is that the comic highlights how strange it is that the "This user has notifications off, Notify anyway?" pop-up can sometimes leave one paralyzed with indecision, despite the fact that it does literally nothing to stop you from sending the text as normal. If it pops up when you send a text, now you have to decide whether your text is important enough to notify the person you have texted, even though they have notifications off. It's the same situation as if you're told that your boss is doing something important. You could be paralyzed, trying to figure out whether "the machine ran out of batteries" is more important than whatever generic "important thing" the other person is doing. Plus, now you have to factor in things like whether your interruption will cause more harm than help, how long it'll take, etc.
If Cueball just "Blocked" notifications from white hat, White Hat would simply be annoyed and just keep talking (because blocking implies that you just don't want to talk anymore.) However, by giving White Hat the option to "Notify anyway", Cueball paralyzes White Hat with indecision, as shown by him not doing anything for multiple panels.
This is ironic, as when users are given the option to "Notify anyway", it basically renders the action of turning off notifications useless because anyone can bypass the system. However, it still works to stop most message notifications, because no one wants to bypass the filter and risk annoying the person who turned off notifications. This may be why Cueball shushes Megan to let it 'keep working'; If Megan speaks up, White Hat might realize that Cueball's 'filter' does literally nothing to stop his messages, and White Hat would resume his rant.
[White Hat, Megan and Cueball are standing next to each other. White Hat is separated from the other two figures by a small margin.] White Hat: And another thing that annoys me about people is... Cueball: This user has notifications turned off.
[The camera zooms in on Megan and Cueball. Megan turns to look at Cueball.] Cueball: They will see your messages when they're back. Cueball: Notify anyway?
[The camera zooms outward to show White Hat. Megan turns back to look at White Hat. All three figures are standing silently.]
[Megan turns to look at Cueball again.] Megan: What are you-- Cueball: Shhh- It's working.
