tongue move around like it would while eating the fruit

mm, I think you may have got something with that idea - the combination of complex mouth movements created by a wide range of consonants and open vowels does seem to suggest a full-mouthed chewing. When you try reading it aloud, there are some really tongue-tangling combinations (mists and mellow fruitfulness) that seem to be quite deliberate slowing effects, building a calm rhythm that suggests the sense of fruition and completion.