How do you depict a bisexual couple? 🤔 How do you depict an asexual couple? 🤔 It's just a lot easier to show two men or two women holding hands. To show that someone is bi, pan, ace, demi, etc. you need to tell a story. Homosexual and heterosexual only require a single picture.
I agree that there should be more representation of the whole community and in books, tv shows, movies and stuff like that it's absolutely possible. But in shorter formats like ads that is a lot more difficult. And who knows, two guys holding hands could still be biromantic and asexual. 🤷 You just automatically assume they're gay because it looks like it in that moment.