This is a companion photo (same scene but different angle) that I posted back on March 6th. In that photo's ID caption there was no explanation of
what was transpiring. The attribution for this photo is the same as the first photo.
There is also a 3rd companion photo of this scene that offers a more detailed explanation of what is going on, and I will use its ID caption to explain photos No 1 and 2 [the 200k cap on embedded images makes posting this 3rd photo more trouble than it's worth].
This train is a livestock & passenger train; apparently it is used to transport livestock (and maybe produce/grain/whatever), and the owners of these agricultural products. None of the captions stated whether this train is bound for a marketplace, or is being used to, literally, change pastures. It was also not noted whether this is a regularly scheduled train, or on some sort of a seasonal schedule. It was also not noted whether there is a fee for such transport.
In many 3rd world countries, it is common practice to transport critters on trains, although the pixs that I have seen of such practice would indicate that there are just a few critters involved [I wouldn't classify Iran as a 3rd world country]. Perhaps in Iran, the road system is, in some areas, not developed enough, etc., to make for efficient/safe 4 season truck transport.
Here in the USA, once upon a time, the RR transport of beef cattle was a really big enterprise, and some major cities had vast stock yards/markets (cattle pens/meat packing plants, etc.,). I have the impression that all of that activity has vanished, at least as far as RR transport goes. The last pix of a RR cattle car that I recall seeing was taken decades ago.