I've had short and long hair. I love long because my hair waves more and it looks nice, kinda elegant when it needs to be and just cool during the day. I also love short. It's cute, looks thicker, and is easier to manage. When I asked my boyfriend if I should cut it he immediately said no. And when I first got it cut short one of my guy friends was freaking out going "noo not your long hair! It'll take so long to grow back!" and etc. So do all guys just have a thing for long hair or what?
Most guys prefer long hair, but short hair does look better on some girls. If that's you in the picture, then I recommend long hair. But, you can experiment if you want. Try different lengths, styles, and ask your friends (Boys and girls) what they think of your hair like that.
I'll say this. Long or not too long all depends. But for sure, short hair, that are really short; like about the shoulders; you really need to be very feminine and pretty for short hair to look good. Personally, I prefer long hair if they are straight. If they are too wavy, then about 8-12 inches below the shoulders are good.