A lot of advice here I disagree with. I don't agree that your leg looks overextended and you should lower the saddle, in fact I think you should raise it slightly. I don't think the handlebars are necessarily too low, but that's your call. It looks like your back is around 45º from vertical (though the camera tilt makes it look slightly more upright). This degree of back angle is pretty normal. Many riders like a position like this. Many hybrid riders prefer a more upright position but not all of us. I don't believe those who are telling you that your handlebars are too low for you are correct. I suspect they mean the handlebars are too low for them. You may prefer a more upright position but the only evidence of that is your suggestion that the bike "feels too small", which by itself doesn't really lead to the conclusions some have made.

I don't know that you are "almost out of seatpost" but it's quite possible. You are almost at full leg extension, so it is also quite possible that your seatpost could be raised to an ideal height without exceeding the range of this seatpost.