You mean a uterus? Sack/uterus makes perfect sense to me.
That's a necklace with a female symbol an ankh.
The bag and male symbol are hardcoded to use the same tile. The necklace and female symbol are hardcoded to the other tile. The third is a leaf. You are now amazed.
Still looks like a uterus. *AMAZED*
Yes, you do have to blow them up to see the sex symbols.
The reason being that those tiles are hardcoded to be shared between game screen objects (bags and necklaces) vs male/female distinction, as Phoebus had mentioned. I tot I'll just clarify a little more since I think I was the one who added the symbols originally
The original set I started with just had plain bags and necklaces. I was quite fed up when culling animals when I can't rem bag is for male or female.. (basically, you kill the female members of the pets that you want to control population, or kill more of the males of those you want to breed) So basically, it is actually TWO things in one tile where some attempt was made to make them seems like one thing... obviously, I can't please everybody. It's a compromise I had to make, not for any fair reason other than I prefer it that way myself (since I modified those tiles primarily for my own use)
If you prefer the items or just the male/female, you can cobble the tiles yourself from the wiki resources (just use some image program to copy and paste)). The original bags/necklace is from Red Jack;s Nintendo set iirc. Or if you really hate the ambiguity (I do actually) but can't live with the ambiguous gfx tiles (I chose to compromise), you might want to just use the non gfx mode, as some people prefers.
My chief complaint with non-gfx version was that is that you can't tell the sub-professions among the same class of dwarves, and the need to memorize/get used to creature symbols esp when seeing them for first time. But in terms of the "ambiguity" due to reusing ascii tiles, it is the mildest or usually the best choice. I always feel that ascii art has its own appeal, though it does have some functional shortcoming as mentioned. It all boils down to personal preference and sense of aesthetics I guess.
Another suggestion: as you get more familiar/advanced, should try to mod stuff to your own liking. gfx set like Phoebus's or Maydays are great starting points, but with those, it is unrealistic to expect them to please everybody. So if you want to please yourself (I sure did those gfx tiles to please MYSELF lol), learn to modify them yourself. Then you can have the game you want (or experience the limitations that other modders encountered firsthand)
rgds