The SU-30 is a big plane. Considerably bigger than the MiG-29 and F-16, and comparable in size to the F-15. See the small picture below showing how large the SU-27/30 and the F-15 are compared to the people around them:
Yes, I did some more searching and realized it it a large plane. In the picture you posted it sits higher off the ground that the F-15.
One thing that is noticeable in most pictures is that the pilot sits deeper in the cockpit. That looks like it would cause visibility issues.