sometimes pictures alone is kinda misleading. well watch the PV and concert and maybe you'll realise why do they want to be visual. take malice mizer for example every member got a role in the band. mana (guitar) as a maid, kozi (guitar) as a joker, kami (drums) ship captain, etc.. there's story in their concert, kinda like musical, they must know how to perform and act on stage as well.
you'll find that if you introduce jrock to others, you'll always receive replies like, is this a guy or girl? is he gay or ah gua? think a little deeper, they're also humans, guys and why do they want to be like that? not because simply they want to be ah gua oh god.. nowadays music is not just purely on playing music.. it's also about art, design and creativity.. and all this merge together with the modern music today..