Is the viewing of pictures on dating sites and applications such as JDate considered to be within the acceptable bounds of halacha or is it more akin to lewdness?
Using a dating website, with the exclusive intent of finding a suitable marriage partner, is considered a legitimate method for trying to find a spouse. However, merely browsing around the website, for some “eye candy”, is prohibited by Halacha.
So you need to be honest with yourself, when looking at these profiles. Is this type of person, a potential matrimonial match for me, and I’m merely checking out her picture to see if she looks pleasant to me, or am I just looking at her picture, because I happen to like to see pictures of good looking women?
You also need to know, that not every profile picture depicts the person the way they look today. The person might have posted a picture of how they USED to look, TEN or more years ago.
I feel sorry for them being in a situation of needing to do so, but it is still dishonest. This is a form of Bait & Switch, when you finally meet the person, and they look nowhere like their profile picture.
If you’re looking for a good modest woman to marry, then you should ignore profiles of women who post immodest provocative pictures of themselves.
Even if they claim that they only did this for “the sake of marriage”; it still shows that they have poor taste regarding matters of modesty, and don’t mind bending Halacha a bit, and being a bit immodest, when they think that doing so will bring them immediate material benefits (a potential partner).