These are what we call the 'YMMV items.' Things that some people find in this work. We call them 'your mileage might vary' because not everyone sees these things in the same way. This starts discussions in the trope lists, a thing we don't want. Please use the discussion page if you'd like to discuss any of these items.
All Hail the King reveals that there is an actual Mandarin who runs the Ten Rings organization that kidnapped Tony in the first Iron Man movie, and he is very displeased with what Trevor Slattery did to his image.
Broken Base: Some fans were displeased by the reveal that All Hail the King would star Trevor Slattery. Though the fact the short reveals that Trev's earned the ire of the real Mandarin (who apparently very much exists) has been a very pleasant surprise indeed for some detractors.
The retcon itself is this for some people, as many liked the Mandarin twist and thought Marvel should just let this one lie with no plans for an Iron Man 4. They also thought that it reflects poorly on Marvel as All Hail the King came off as a middle finger to Shane Black and felt like a thin-skinned move to appease the detractors.
Growing the Beard: The first short comprises of nothing more than a clip from The Incredible Hulk bookended by clips of SHIELD agents conversing at a table. The following shorts rely more heavily on original footage, and boast more interesting plotlines.
And now Marvel's thinking about using them to test new characters and seeing if they're received well enough to make the jump to the movies.
Ho Yay: Justin Hammer at the end of All Hail The King seems to have a prison butt buddy that follows his every move and order without a word. His talk about Tony Stark and his jealousy of him also questions his orientation.