The images you've provided show what would have been the fashion for the urban upper classes (or the large landowners, who didn't do the manual labor themselves). You can tell because of the precious metals and jewels inserted into the weave, and also the sheer impracticality of some of those outfits--you can't exactly work in them (that's why they were so outlandish; they proclaimed to everyone "look, I have an army of servants to wait on me!")

The vast majority of Egyptians were peasant farmers who wouldn't have dressed much different than they do now. The robes (galabiyas) might have been made out of linen instead of cotton and were probably a much more sheer, semi-transparent weave. Based on the images in tombs, it's possible that it might have been more common to see men working in the fields nude or semi-nude rather than in robes (in terms of sun exposure and dehydration, it's actually better to be covered).

It also appears that shaving the head was fairly common (theorized to have been a preventative for lice), so some sort of headdress--probably a simple cloth--would have been used to prevent sunburn.

The acceptance of nudity in the fields would have been tamped down in the Christian era first (they weren't much more tolerant of it than the Muslims who came after them) although in rural areas such "scandalous" behavior was occasionally and breathlessly reported by European travelers as late as the 18th century.

For more on what we know about "normal" people, check out Barbara Mertz's Red Land, Black Land: Daily Life in Ancient Egypt.