Mail
Mail
[Cueball is talking to someone through a phone.] Phone: Do you think I could mail a running chainsaw to someone? Cueball: I doubt it Phone: What about a baby's first word? Cueball: Look, your obsession with sending strange things through the mail is getting out of hand.
Phone: Can you mail a blank stare? Phone: A dizzying height? Phone: Pi? Cueball: ...
Phone: Well, did you at least get that package of time I sent you? Cueball: I... you... no, I didn't. Phone: Well, there was a lot of it, so it will probably take a while

Cueball 's interlocutor is working their way through a list of increasingly impractical or impossible suggestions for things to send through postal mail. The pay-off is that they have already somehow sent a package of time through the mail, and this is taking a while to arrive, presumably because the amount of time it will take to reach the recipient is equal to the amount of time being sent. By the time it reaches Cueball, the time will have passed, and therefore not be of much use.
The reference to a 'package of time' could refer to quantizing time ("discrete packets of time") - a theory that time is not continuous as particles in the quantum mechanics . It could be one of the big mistakes in modern science, but feels as if there's more to it, in the world of romance, sarcasm, math, and language.
A no-fly list is a list of people who are not allowed to use commercial airlines for travel. In the United States, it is maintained by the Terrorist Screening Center . According to the title text, the person sending strange objects through mail is on a no-fly list for the United States Postal Service (USPS). While the USPS has a list of items banned from being shipped in the mail, which includes most consumer electronics with lithium batteries, it does not have such a list for people. This could suggest that this person has attempted to send so many strange items that USPS will no longer accept mail from him, or it could imply that they attempted, at one point, to send themselves via air mail, and have been banned from doing so again.
This comic might be related to W. Reginald Bray , an Englishman from the turn of the 20th century, who was famous for mailing unusual objects (including himself) to experiment with the postal system.
A list of the things:
[Cueball is talking to someone through a phone.] Phone: Do you think I could mail a running chainsaw to someone? Cueball: I doubt it Phone: What about a baby's first word? Cueball: Look, your obsession with sending strange things through the mail is getting out of hand.
Phone: Can you mail a blank stare? Phone: A dizzying height? Phone: Pi? Cueball: ...
Phone: Well, did you at least get that package of time I sent you? Cueball: I... you... no, I didn't. Phone: Well, there was a lot of it, so it will probably take a while
