It does not appear that Bob has committed a U.S. crime.
18 USC § 2252(2) quoted in the OP does not apply because the question states that the material does not fit the definition of child pornography in that statute (unless the federal government can establish that the visual depiction was drawn or painted, rather than photographed or video recorded, from children engaged in sexually explicit conduct).
The territorial application of 18 USC § 2252(2) in cases where actual child pornography as defined in the statute is transmitted is arguably applicable. The general rule is that a crime can be prosecuted where it is committed, or where it has an effect. If a child victim were U.S. based, the crime committed by Bob abroad would arguably have been committed, in part, in the U.S. But, there is also a presumption that U.S. criminal laws do not have extraterritorial application unless their terms clearly show a contrary intent, which isn't terribly clear here (although I haven't seen a case directly on point).
18 USC §§ 2251(c) and 2260(a) also do not apply because the content is being exported from the U.S., not imported to the U.S., so even if it was child pornography, it wouldn't be within the scope of those offenses.
I have not scoured Title 18 for other offenses that could conceivably be implicated.
To my knowledge, the answer will be no as 18 USC § 1466[A] only applies
extraterritorially to the special maritime and territorial
jurisdiction, so not a foreign country, but I’d like to hear some
takes on this.
I do not have an affirmative answer to this question. It would take more time to research and evaluate than my interest in extraterritorial application of U.S. child pornography can support at the moment.
However, the conclusion in the quoted material above is not supported by the statutory language. The pertinent part of Section 1466A (i.e. 18 U.S.C. § 1466A(d)) has five subsections connected by the word "or". Specifically this states (emphasis added):
(d)Circumstances.—The circumstance referred to in subsections (a) and
(b) is that—
(1)any communication involved in or made in furtherance of the offense
is communicated or transported by the mail, or in interstate or
foreign commerce by any means, including by computer, or any means or
instrumentality of interstate or foreign commerce is otherwise used in
committing or in furtherance of the commission of the offense;
(2)any communication involved in or made in furtherance of the offense
contemplates the transmission or transportation of a visual depiction
by the mail, or in interstate or foreign commerce by any means,
including by computer;
(3)any person travels or is transported in interstate or foreign
commerce in the course of the commission or in furtherance of the
commission of the offense;
(4)any visual depiction involved in the offense has been mailed, or
has been shipped or transported in interstate or foreign commerce by
any means, including by computer, or was produced using materials that
have been mailed, or that have been shipped or transported in
interstate or foreign commerce by any means, including by computer;
(5)the offense is committed in the special maritime and territorial
jurisdiction of the United States or in any territory or possession of
the United States.
Thus, only one of those five parts of that subsection must be present for the statute to apply. A location in the special maritime and territorial jurisdiction of the United States (which is not, strictly speaking, extraterritorial anyway, this is just a special subset of U.S. territory outside any U.S. state or the District of Columbia), is sufficient to bring the statute into play, but is not the only way that it can be implicated. Any of the other four parts of that subsection could also trigger the application of the statute.
The statute does not expressly state whether it has extraterritorial application on its face, so one is left trying to weigh the presumption that U.S. criminal laws do not have extraterritorial application unless they say otherwise, against the language specifically contemplating the use of "foreign commerce" in a way that doesn't unambiguously treat importing and exporting regulated material differently.
Also, because the statute does not require that the depiction be of an actual instance of a child engaging in sexually explicit conduct, the default criminal jurisdictional analysis over whether either the criminal act, or the consequences of the criminal act took place in the U.S. is less clear.
Further, there are issues over whether a visual depiction that did not involve an actual minor is indeed constitutional under the First Amendment.
Each of these case law driven considerations is weighty and the subject to a significant body of complicated to apply case law that isn't perfectly consistent internally, so it is quite challenging to determine as a matter of law whether this law would apply to Bob in this fact pattern, unless there is an almost identical case that has squarely addressed this fact pattern and isn't implicitly repealed by later decisions of higher courts.
So, I can't answer how this question would be resolved legally one way or the other with any confidence at this point and I am not willing to do the substantial additional research that would be necessary to make this determination (which would probably reach the conclusion that there is not a definitive answer in the law at this time).