is this the ultra-IQ phenotype?

[Steppenwolf]

I think it has a lot to do with the portrait style artists used back then. a lot of the time they would change features of the irl people to actually make them look like some conventional pheno. 

realistically if you look at geniuses from say the 20th century where we had photography most looked pretty different IE turing, tesla, wittgenstein, fischer, rachmaninoff, etc...

they have the phenotype, tbh

i mean your point above is reasonable. but there are written descriptions, and more paintings from different angles. 
i don't think the 'strong' nose traits they share and the above average skull height would be portrayed so consistently if were so

the sharpness of their features indeed connects them but high iq individuals do also tend to be skinny very often. there are lots of examples of the big noses but also lots of counter examples, i dont know, there doesnt seem to be enough evidence to this.

fair