Well, addressing the scale, I think they focussed on having a sphinx-like secret chamber, I guess.
It is a reasonable sized set, I like it, even though I have to admit that this is the only one I did not buy, actually.
And to the face... Well, they decided to not make it playmobil-style. Maybe their first drafts did not look cool enough?
Also in the pyramid, the reliefs on the side walls show a pharao with a human and not a klicky face.
Maybe evolution drove them into their nowadays shape and 4000 years ago the klickies looked like human?
best,
socrates