Like Parzival and Silence, the poems in these excepts emphasize an ideal of beauty that is not gender specific. The young men of the Hebrew love poetry and the cup-bearer of Al-Sharif al Taliq's poem are both described in what we would now consider to be feminine terms - the lips, flushed cheeks, slender thighs and thin waist are all physical attributes that we would not consider fully masculine today. Rather, they are signs of youth, boyishness, or femininity - all qualities that make the young man of the poet's gaze an object of desire to the presumably older man.
(This makes me wonder if there is much poetry celebrating masculine beauty from this time. I would think that objectifying a full-grown man would be seen as transgressive, as would the expression of female desire, but I could be wrong.)
What I thought was most interesting was Serrano's comment that the sex of the beloved in Al-Sharif al Taliq's writing is actually not known, nor is it important: "The use of the masculine pronoun in referring to the beloved...does not necessarily mean that he is male. Love poems of this period sometimes addressed women with masculine pronouns and masculine forms of nouns. The gender of the addressee here is ambiguous and probably irrelevant" (153).
According to Serrano, all extra-marital desire was considered illicit, so the desire of a man for a young man instead of a young woman would not have been thought of as any more scandalous to express. Where we would now view the divide between homosexual and heterosexual desire as stark, the line between marriage and non-marriage was the primary consideration.