Ah -- an excellent question. She sees that he has a hard time coordinating his face and mouth muscles to make sounds and words. Initially she saw him "groping" with his face and mouth before making any sounds or words, but that happens very infrequently now that we're six weeks into therapy.
His current obstacle is adding a consonant on the end of a vowel (e.g., in, up, on, open). His motor skills are otherwise quite good (he walked at 9.5 months), including fine motor skills using hands and even feet. It's daunting how much coordination he has, even with chubby little two-year-old fingers!
Thank you for the question!