There are all these ridiculous new movements, and in some cases actual laws, to force women to get a transvaginal ultrasound before an abortion, even when it's not medically required. Some people have responded to it by saying that if women don't want to see the images, they can close their eyes, and others have said that if women don't want an ultrasound wand in their vagina, they shouldn't have put anything else (PENIS!) in their vagina. These responses seem to be missing the point that, in situations where it isn't medically required, it basically exists to function as an additional uncomfortable, unpleasant punishment. Equating the wand to a penis is especially odd, since dicks and hard plastic ultrasound wants don't actually have a lot in common.
But the main idea seems to be that women who have sex shouldn't mind having something else shoved up their vag. I'm actually surprised I haven't seen it compared to a dildo yet, since they have similar general shapes, but that comparison would fail too, especially since the vast majority of women who use masturbation aids use external vibrators, rather than internal vibrators or dildos (their are actually statistics on this out there if someone wants to go hunt them up, but I'm not exactly in the mood to wade through the kind of search results that query would get).
The main thing is, though, that a transvaginal ultrasound is fundamentally different from sex. During sex, if a "normally" functioning woman is interested, her vagina actually lengthens, lubes up some, and widens. Penises are rigid, but also bendy. Time and angles can be navigated to provide pleasure, or diminish discomfort. In a transvaginal ultrasound, you're probably not aroused, so the vag is going to stay its typical, unwelcoming size. The wand is going to be hard plastic with no bend and no give. And rather than working for comfortable, pleasing angles, the thing gets purposefully moved around and held in positions that, well, can hurt an awful lot and be just plain uncomfortable when they don't hurt.
This isn't speculation. I had to have a transvaginal ultrasound a couple of years back as part of a diagnostic procedure, because it really can see what's all up in your abdominal cavity business. And it hurt and was unpleasant, and was basically way awful. It helped that the technician was super kind and tried to be gentle, but still. To get some of the pictures she was needed, it involved a lot of super unpleasant maneuvering and felt even more vulnerable than a regular gyno visit. It wasn't the worse pain I've ever felt, and I wouldn't rank it up as one of the worst parts of my life, but if someone told me that I had to have one when it wasn't even medically necessary, to try and make me reconsider my previously made health decisions, when it wouldn't truly add any new information to my decision-- God, I'd be furious. It is not a pleasant procedure, and it is not some little inconsequential thing. It is painful and unpleasant and when it isn't medically necessary it's useless. I can't see how requiring women to have a transvaginal ultrasound before an abortion is anything other than a punishment, meant to discomfort, shame, humiliate, and possibly hurt women. She already knows what's in there. That's why she's getting the abortion. What purpose does showing her a grainy image, indistinguishable from a stock image actually serve?