Their predicted skull shape was broad and elongated.

Their brow ridges were probably substantial.

Their faces were probably large and projecting.

Their dental morphology, as directly observed in the recovered molars, was notably primitive.

For Denny specifically, the question is even more complex.

As a hybrid, she would have inherited a mixture of Neanderthal and Denisovan genetic variants, and the expression of those variants in her physical form would depend on the dominance relationships between them.

Some Neanderthal traits might have been dominant in her, others recessive.