If you are flying out of Orange County, SNA, you'll see
a high pitch attitude for takeoff, about 20-23 degrees due to the noise abatement procedures. Normal takeoffs will result in pitches from 15-20 degrees, dependant upon aircraft weight and flap settings used.
The pitch attitude on initial climbout is used to keep the 757 at V2+15 until 800-1000' AGL where the pitch is cut about in half (If you were climbing out at 20* you would lower the nose to about 10*, but not less). The flaps will then be retracted according to schedule until flaps are at 5* and climb power is set. The plane will then be accelerated to 250KIAS, which should be reached around 3000' AGL.
Some airports may also be a factor in the climb-out pitch attitude.
I have experienced the powerful take-off with high angle of climb a few times. I think it has something to do with noise abatement procedures (I took 757 from LGA several times). But I think it also has to do with the powerful RR engines on the 757. As I remember, the take off power on AA 757 felt a lot more strong than DL 757.