@Alex Knights,
If you feel confident that the reason you weren't chosen was because of the picture, then definitely go see if a lawyer will work on it for pro bono. As long as it doesn't cost you anything, and you feel certain they are in the wrong, then absolutely go for it! If they said longer income, but only required 2 years of W2s, then they likely confirmed with the employer that they'd been at their job for X years. If you have the time, and feel confident about the case, go for it! Just a thought, if you really want to determine if that was/wasn't the case, find another property they are renting.. and create 2 alias, very stereotypical names and stereotypical writing, , and see if they tell you it's rented, and it's available to the other? That'd be a case I'd bring to a lawyer!
As far as the discrimination goes, I'm a woman in real estate. It's kind of normal. I have contractors state that they will only talk with my husband, and I think we're up to 3 complaints about me this year, where they say I'm too outspoken, and threaten not to work with us because I'm too "direct." Some men are really uncomfortable with women as their boss, at first I was offended, but then you just realize it's a part of life, and get thick skin.
I also have seen discrimination from banks, who wouldn't lend to us because the area we invest in-- "What kind of people do you rent to?!" they immediately think we're slumlords, or the properties are only section 8, stuff like that.. whereas our houses are gorgeous, and we only rent to hard working people! I complained to the guy's boss, but she essentially just stood up for him... so it was useless,... It's just a part of the game, and when we see it, we direct our business elsewhere.