This is The Sirens and Ulysses by William Etty (1837). Dear oh dear... At the time the critics called it obscene, and even today it's in gloriously poor taste. There's the sirens, see, waving their boobies and singing to Ulysses across the water while his men (who've got their ears stopped with wax) are holding him back from leaping overboard. All around the sirens are the decaying bodies of those sailors who succumbed in the past to their lure, some reduced to bones and some just yucky. Sex 'n' death, eh? Bear in mind that this picture is enormous (and actually really brightly coloured in real life). It's currently being restored in public (it has its own exhibit) and I think it's just wonderfully, embarrassingly grim and pervy.
Here's another - rather more famous - picture they have on display: Sappho by Charles-August Mengin (1877). I actually have a print of this behind me as I type, because it's been one of my favourites for years: for some reason I'd imagined the original as being quite small. In fact it's well above life-size and truly dominating.
On the other hand this picture: Silver Favourites by Sir Lawrence Alma-Tadema (1903), which I'd always imagined to be huge, is only about A2 size.
And this one (Astarte Syriaca, by Dante Gabriel Rossetti)? In the flesh, quite powerfully ugly.
Art, it's a funny old thing...