Incidence of reflections are completely different in those two examples - the lake is at grazing angles so the reflection value is close to 100% whereas the particles on the tiles is getting towards 0 degrees (to the eye ray) and so would be closer to 4% = major difference. Remember a tiled floor is a dielectric and a mirror is backed by a layer of metal which is a conductor and so can reflect at 0 degrees at almost 100%.
Your example looks physically correct to me - but perhaps you just want something stylized which is fine.
I’ve got another thread going on HDR - but this new behaviour is critical to having HDR display correctly and not look bizarre that there’s a ‘bright’ colour causing bloom which in HDR is actually barely bright and then a particle system next to it throwing sparks with correct Black Body levels is scorching hot then the skybox behind everything is flat and dull because it’s a low dynamic range jpeg.
Of course i’m only talking about photo-realistic rendering. Unreal makes some great cartoon/stylized stuff so there needs to be modal behaviour to support every avenue.