Here's something we haven't seen before: what appears to be a Starfleet Honour Guard uniform in the JJ-verse. These guys are wearing the same pattern of dress uniform as Kirk, Scotty and Chekov but in black (or possibly very dark grey).
The obvious things are the grey (or grey-blue gloves and the similarly coloured sash over the right shoulder;
More subtle details are that it is possible to make out the same buttons on the epaulettes with the embossed delta emblem and on the fron of the cap worn by the figure on the far left you can just make out the same style of cap badge as those worn by Scotty and Chekov (the one with the two "laterally" placed deltas set like "wings" behind the main delta symbol — this is actually most visible in the third picture below, the one with the more unfolded flag.
They are also wearing black belts around their waists and the tops of metal buckles can be seen at the front but design details are not visible. On their shoulders they wear (huge...!) versions of the Starfleet "Commamd" symbol (the elongated five-point star). Their main Delta badges on the left breast appear to be without any central symbol, like those from the 2009 movie.
Again, I've included a slightly closer shot that shows some details a little more clearly. I've also added in a shot from the transition from the previous scene as this best shows the new design of Federation flag that they are folding (presumably this is a funeral ceremony...?). The design differs somewhat from the version we are used to. They do not appear to have any visible cuff rank insignia.