What ore minerals are likely to be found in a thin section like this? What can we deduce from the structure?
Sulfide ore petrography is reflected light is even harder than transmitted light. Unlike transmitted light, colour is actually a very important characteristic feature. But the perception of colour can vary between different light sources, quality and time since polish, microscope lens, and cameras. Therefore, from an image like that it is extremely challenging to tell what the minerals are.

In my opinion you have two of either chalcopyrite, pyrite, pentlandite, pyrrhotite. It is very hard to tell. My guess would be pyrite (the bright one) and chalcopyrite/pentlandite (the golden one).

In cases like this, as a way to move forward, do one or both of the following:


Have thin sections where you know the identity of the minerals so you can compare with your unknown, on exactly the same analytical conditions.
Get access to an EDS-SEM system. I know it's easier said than done, but nowadays these instruments are extremely common in almost every research institution, and once you're experienced it takes literally minutes to identify the minerals.