Peter's answer explains one aspect of the appearance of the engine angle being the way it is between the -200 engine angle relative to the angle of attack on the ground versus in the air and between the -200 and the -8.
There are also the considerations of FOD (foreign object debris) entering into the engine and the account for accessories off of the engine that are concealed by the cowlings. FOD is handled very different today (using bleed air screens) than when the -200 was designed when the angle on the engine's inlet was used. As far as the accessories that are concealed under the cowlings, they are also vastly different.
Another thing that drives the shape and size of the fan cowls is the bypass ratio. For the -8, the bypass ratio at takeoff is 9.0/1, so 90% of the air going through the fan goes into the bypass section. For the -200, the bypass ratio is 5.72/1, so roughly 83% of the air is bypassed. While the doesn't seem like a large difference, the geometries are significantly different. Those differences mean that the risk of FOD going through the fan versus the core are different and yield different inlet angles.
Other factors that make the appearance of the overall angle being different between the two versions are going to be side slips inlet designs and just the camera angles taking the pictures. The overall angles of the engine itself may not actually be that different.
tilted up to "meet the air at a streamline angle"
Where did you quote this from? $\endgroup$