How might the way Sumerians thought about their god differed from the way Egyptians viewed theirs?

You are talking about a period so far back that we don't actually know anything. We talk about "Mesopotamia", as if it were a place, but the name only means "between the rivers". The rivers were Tigris and Euphrates, and that is a lot of ground. We talk about "Indus Valley" as if it were a city when in fact it was over a thousand cities. We talk about "Sumerians", forgetting that we have no idea who those people might have been, what they believed, where they lived, or anything else. Egypt is also pretty much unknown. We have three lists of kings, but they don't have the same names and they are not in the same order. There is a 500 year discrepancy between Egyptian history and the histories of the surrounding areas. Besides that, there are dozens of conflicting histories, each firmly believed by its proponents. For instance a lot of people casually assume that Egyptian pyramids were tombs, but no dead body has ever been found in an Egyptian pyramid. The confusion arises because pyramids in surrounding areas usually were tombs. Another confusion factor is that so many people simply make up bs and present it as valid history, especially religious history.