I imagine there are various feminist readings of Joyce’s writings and Ulysses in particular. The female characters are present and rich, both sympathetic and in charge. Powerful is a bit of a cliche word to describe strong women, but it is aptly used here where the various female characters, in 1904, are in control of their lives, their desires and, often, the men around them.
I’m no literary critic, but will say Joyce’s understanding of women and multi-faceted depiction of them is, however unconsciously, partly responsible for my love of the book and sense of kinship with its author and central character alike.
Enter the Sirens, Miss Douce and Miss Kennedy. They stand behind the bar, their hands caressing the phallic beer knobs, while the men, acutely aware of them but at a distance, are continually drawn to them (necessarily so to obtain a drink, but this is beyond the point as motivation doesn’t interest us here as much as movement). The women are protected by the bar itself and by their own ridicule and scorn for the men generally and Bloom specifically.
They are only vaguely sexual, teasing the men, but primarily they are only to be contemplated — viewed. They are distinct from the Sirens of Odysseus in that a vocal chord does not pass their lips. The singing is left to the men. Music serves many purposes within this Episode, but largely I see it as nostalgic — allowing the men to retreat to the past, to someplace other than where they are, a reverie of sorts created by themselves rather than the seductive female.