When in doubt, don't depend on opinion but go to the source documents themselves.

Here is the definition from the 1984 Convention against Torture and Other Cruel, Inhuman or Degrading Treatment or Punishment:

Article 1

1. For the purposes of this Convention, the term "torture" means any act by which severe pain or suffering, whether physical or mental, is intentionally inflicted on a person for such purposes as obtaining from him or a third person information or a confession, punishing him for an act he or a third person has committed or is suspected of having committed, or intimidating or coercing him or a third person, or for any reason based on discrimination of any kind, when such pain or suffering is inflicted by or at the instigation of or with the consent or acquiescence of a public official or other person acting in an official capacity. It does not include pain or suffering arising only from, inherent in or incidental to lawful sanctions.

A more recent reference from Human Rights Watch states:

Q: What is torture?

The Convention against Torture defines torture as "any act by which severe pain or suffering, whether physical or mental, is intentionally inflicted on a person for such purposes as obtaining from him or a third person information or a confession…." (Art. 1). It may be "inflicted by or at the instigation of or acquiescence of a public official or other person acting in an official capacity."

The prohibition against torture under international law applies to many measures—e.g. beating on the soles of the feet; electric shock applied to genitals and nipples; rape; near drowning through submersion in water; near suffocation by plastic bags tied around the head; burning; whipping; needles inserted under fingernails; mutilation; hanging by feet or hands for prolonged periods.

International law also prohibits mistreatment that does not meet the definition of torture, either because less severe physical or mental pain is inflicted, or because the necessary purpose of the ill-treatment is not present. It affirms the right of every person not to be subjected to cruel, inhuman or degrading treatment. Examples of such prohibited mistreatment include being forced to stand spread eagled against the wall; being subjected to bright lights or blindfolding; being subjected to continuous loud noise; being deprived of sleep, food or drink; being subjected to forced constant standing or crouching; or violent shaking. In essence, any form of physical treatment used to intimidate, coerce or "break" a person during an interrogation constitutes prohibited ill-treatment. If these practices are intense enough, prolonged in duration, or combined with other measures that result in severe pain or suffering, they can qualify as torture.

The prohibition against torture as well as cruel, inhuman or degrading treatment is not limited to acts causing physical pain or injury. It includes acts that cause mental suffering—e.g. through threats against family or loved ones. As the U.S. Supreme Court has recognized, "coercion can be mental as well as physical…the blood of the accused is not the only hallmark of an unconstitutional inquisition" Miranda v. Arizona, 384 U.S. 436, 448, (1966) citing Blackburn v. State of Alabama, 361 U.S. 199 (1960). As discussed below, the use of mind-altering drugs to compel a person to provide information would at least amount to inhuman or degrading treatment under the Convention against Torture.

There was a recent update to the convention cited above, but I have not found the actual text, so I'm not certain what it says.

Those definitions are still pretty vague, IMO. I did see examples of mental abuse of those prisoners, but whether that abuse rises to the level of torture as defined by these treaties is debatable. I saw little or nothing that compares to beating on the soles of the feet; electric shock applied to genitals and nipples; rape; near drowning through submersion in water; near suffocation by plastic bags tied around the head; burning; whipping; needles inserted under fingernails; mutilation; hanging by feet or hands for prolonged periods. Perhaps I missed it. I agree that the abuse was not only illegal but stupid, so those responsible must be held accountable. I just didn't see torture, even by the vague definitions cited above.

As some former POWs about the torture they endured compared to the abuse in those prison photos. I suspect most would say there is no comparison. I'm certain that my Uncle Paul (Korean War POW for 30 months) would say so.