Why brows....

The most obvious answer to why the Malayoid had such well developed brows is that they served to reduce glare much as our own appear to do.

Glare from a bright light source, such as direct or reflected sunlight, causes a reduction in contrast between the task (that which is being looked at) and the glare source. Disability glare is often caused by the inter-reflection of light within the eyeball. (Wikipedia)

The eagle and most other raptors also have a prominent brow ridge that gives them a distinctive stare. The Asiatic games are said to have a cruel look, a bit of anthropomorphism, as a bird cannot change it's expression like a person. Perhaps the intense stare of anger in humans serves to improve vision by lowering the usually dark eyebrows which would serve to reduce glare and increase the contrast of the object being stared at!

It must serve an important function. In raptors it would appear to be related to their need for visual acuity from a great height in bright sunlight. Perhaps the Malayoid also searched for food under bright sunlit conditions. The Red Jungle Fowl is a graminiverous feeder, like most chickens, doing more intense scratching with their clawed toes than other pheasants, picking out tiny seeds and other particles of food. They also put away a fair amount of grass and forbs and have no hint of a brow ridge whatsoever.

It is very possible the Malayoid was more carnivorous in it's diet. Many domestic fowl can and do develop a taste for flesh.

The Malayoid fowl had a strong "delta" beak, possibly designed to crush insects or crustaceans.

 This is a North Indian Kulang fowl. Note the heavy beak and the fleshy skin growing out over the proximal portion of the beak. Malayoid would have had an even shorter more rounded head with almost no break in the curve between skull and beak. Note the exposed conjunctiva in front of the eye often seen in common breeds. This tells me the head must have been shorter.



Here's another one:

 This is Sadie, a very strange Shamo hen. No exposed conjunctiva here.



And one more....

Note swollen cheeks, common in these birds.

So what do you think these birds ate?