Basically, this is the idea that the language we speak shapes our thoughts and our perception of the world. Linguistic relativity is actually a rather old concept with a long history harking back to Plato. It makes sense intuitively, that how we would describe something is necessarily linked to what we notice and thus affecting what we consciously perceive. A recent study was done with Greeks and Germans with EEG (electroencephalography) showing that indeed the language a participant spoke seemed to affect an area of visual processing.
(this has since been somewhat disproven by ‘grue’ languages: participants in a study that speak a grue language (languages with the same word for green and blue) could still distinguish between the two colours.