The article is about what you would expect from the title, al-Rubaysh discusses what he terms the three stages of confrontation by the Shi'a, who he says want nothing more than to harm Sunnis. Most who are familiar with this type of literature can fill in the various insults and statements made by al-Rubaysh, but for me the most interesting parts were the three anecdotes he used to illustrate his points.
In the first stage - the stage of weakness - he discusses a friends attempt to buy an 'iqal - the often twin cords worn around the headscarf which can also be used to hobble a camel - in Saudi Arabia's eastern provinces. Buying from a Shi'a merchant his friend found was much too expensive, but when he went to another store and purchased an 'iqal he found it much cheaper. Of course the second merchant was a Sunni. The implications are obvious.
In the second stage, which is just when the Shi'a are beginning to feel powerful, he mentions the clash between some Islah supporters and some Huthi supporters a few months ago in al-Jawf. In this stage the Shi'a, according to al-Rubaysh, begin to flex their muscle.
In the third stage he finally talks about the Huthis, but is open about how confused and muddled the situation is - although his words should put to bed the Saudi and Yemeni stories that AQAP is allied with the Huthis.
A couple of things stand out to me from the article. First, it is interesting and I think indicative of the Saudi influence on AQAP that the organization would publish such an anti-Shi'a article. I don't remember Sada al-Malahim publishing similar articles previously, although I would have to double-check to make sure. I don't think a Yemeni would have written such an article, particularly given the thin line between Sunni and Shi'a (Shafi'i and Zaydi) in Yemen. Also it is, in my opinion, a bit of tactical mistake to come out and label Shi'a in Yemen similar to Shi'a in Iraq and Gulf countries.
I think this is one area that AQAP may actually end up distancing itself from its target audience in Yemen, given how Yemenis are well aware that Zaydis are not Twelver Shi'a. For those looking for cracks in the AQAP armor, I think this is one.