value error of incompatible wrong dimension during training a model
As per the documentation, whenever the transformer expects a 1D array as input, the columns were specified as a string ("xxx"). For the transformers which expects 2D data, we need to specify the column as a list of strings (["xxx"]).

so the code below will work.

## Important: i have passed the columns a string to CV and list of columns to OHE

transformer=ct(transformers=[('review_counts',cv(),'verified_reviews'), 
                             ('variation_dummies', ohe(),['variation'])
                            ],remainder='passthrough')


Credit goes to Another man who helped me on this.