To me that symbol looks more like a "straight emblem" but only by contrast to other bisexual symbols I know.
With bisexual symbols you usually have some indication of the bisexual individual themselves in relation to the gender symbols, I guess in this case Ivy herself as the canvas serves that purpose. Most often though this symbolism is portrayed as the symbols having been combined, so a circle with both the arrow and the cross, though this symbol is often used by genderfluid individuals also, the symbols of course showing gender identity rather than sexual preference to them.
I don't have a tattoo of it, but I have a small pendant that I purchased a long time ago that's meant to symbolize bisexuality and in that one there is a third circle in the middle interlocking with the male and the female symbols. This is of course meant to symbolize the bisexual person in the middle, me in this case, and how I then relate to the two genders I am attracted to.
Ivy's tattoo is just a male and a female symbol locked together in a heart. It could of course mean that those are the genders she's attracted to, but I'm not sure that'd be the impression I'd have if I encountered it IRL.
Maybe it's just meant to symbolize "yay sex"
