Like most public markets in Guatemala it is very crowded, yet interesting. Unlike most public markets in town squares this one is mostly inside a building rather than outside under tarps. So, it has a quite different feel to it. One should also realize that this market, like most such Guatemala markets outside of Guatemala City and Antigua are there for the locals rather than the tourists. This one in particular was for the most part produce and meat. You may find a craft market somewhere nearby.
Here you willl find all manner of fish, produce and meats. Except for a
few formal shops around the perimeter most of the venders just lay out
their goods in baskets or on mats on the floor. Some bring a some saw horses and lay
plywood across them to make a table top.
As in much of the country, the people here are very photogenic. However, they are for the most part reluctant to be photographed unless you engage with them and buy something - or at least give them a bit of money. If you are fortunate enough, you could be with a guide who in prior years had photographed many of the people in the market and brought prints to give them.
If you are a photographer, this building offer some vantage points not normally available in public markets. There is a concrete stair well with open sided where you can shoot down into the market without being in the thick of it (once you get to the stair well). On one side there is also an mezzanine sort of area, half a story above the market floor where you can see down into the market.
So, if this is your sort of thing, this may be worth a stop.