IMO your room is not too small. There are other issues at work here, synergy being the primary I believe.
Not sure where you're going with the 'glass' question but certainly it reflects. I had a pair of split glass doors on my heavy wooden component rack (which I very rarely closed anyway). One day the cats were roughhousing & banged hard into one open glass door, stripping out a hinge woodscrew. In the process of effecting a repair, I removed both doors from the rack. The rig was playing & as I was walking around the house I noticed an improvement (a reduction of midrange glare, which I had been trying to figure out for some time). Following some brief critical listening, we decided that those glass doors were never again going to be installed.
Not sure where you're going with the 'glass' question but certainly it reflects. I had a pair of split glass doors on my heavy wooden component rack (which I very rarely closed anyway). One day the cats were roughhousing & banged hard into one open glass door, stripping out a hinge woodscrew. In the process of effecting a repair, I removed both doors from the rack. The rig was playing & as I was walking around the house I noticed an improvement (a reduction of midrange glare, which I had been trying to figure out for some time). Following some brief critical listening, we decided that those glass doors were never again going to be installed.