How much do you want to reduce the size?
You would have to double the amount of steel just for strength and deflection will be an issue
We don't determine beam sizes for aesthetic reasons. I can't size a beam without loading and deflection criteria.
7 kips/sq ft is not in any universe a realistic load.
I'm going to opt out. You've provided no information to help me answer this question. I want to help, but I'm not a mind reader and neither photo that you've send shows a concrete beam.
You've given 0 criteria to design a beam other than the span.