The scene shown in those photos is shown in a video clip in this news report, transmitted yesterday. It runs from 59 seconds in to 2 minutes 14 seconds. The location, the trench, the truck & the people are all obviously identical.
Russia Ukraine conflict: Food and water running out in devastated Mariupol
I've seen other fragments from the same scene. Haven't found the one with the woman's legs again, though. I'm trying to remember where I saw it. I've seen a lot of scenes shown in multiple reports, sometimes from different angles.
When you're in a siege, short of everything including potable water, & a lot of people are being killed, elaborate funerals tend to be thought of as an unnecessary luxury. At least they're being buried, not left in the streets.
Of course elaborate funerals are out of the question. What I saw in the video is exactly what I would expect to see in that situation. What I saw in the photos was a bit questionable, as those photos showed bodies loosely wrapped in nothing but a sheet or slung from a tarp.
When all the body bags, industrial waste bags, etc., have been depleted, bodies are normally encased in large trash bags or at the least, inside duvet covers and the like (garbage bags preferred, of course).. Bodies of people killed by the enemy are rarely just thrown in a ditch with little to no covering -- people really do try to do their best for loved ones, neighbors, fellow citizens even in such dire circumstances, at least in my own sad experience. It also makes the task less gruesome for the burial crews. Bodies of the enemy or the wrong ethnicity sometimes do not receive such care (duvet cover, etc.). Again, according to my own sad experience, which was not in Ukraine, but places where similar scenarios occurred.
The photos gave the impression all or most of the bodies were not encased in anything other than a loose sheet or tarp, with no attempt made to even twist the sheet so the body did not so easily fall out before dumping. This would indicate a total breakdown of organization and loss of humanity if the bodies were those of fellow citizens. While the situation in Mariupol is indeed dire and utterly heartbraking, one would not expect to see such total breakdown, at least not yet.
After viewing the video, I heard what I expect to hear (crews organizationed by municipal authorities for the task) and saw what I would expect to see. As for the bodies with little to no covering in the photos, several scenarios are possible, all of which are tragic.
Edit: There is much more to the suffering in these circumstances than war casualties. When the shelling starts, pregnant women go into labor, people at risk for stroke or heart attack have strokes and heart attacks. Emergency and medical personnel can be overwhelmed. More babies, including premature babies, than usual are being born, more stroke and heart attack victims -- and this on top of those injured in the shelling, etc. And this is just in the beginning. As time wears on, there are new tragedies.