I presume the parent means changing the data s.t. the max length of strings in a column changes; this would cause the padding after that column to change, so as to keep subsequent columns aligned & looking nice. This doesn't play well w/ VCS diffs, as a bunch of data that isn't changing semantically is now changing syntactically, and a simplistic textual diff reflects now that syntactic change, whereas a human reader would want to see the semantic change.
Now… most diff tools also have options to ignore whitespace changes, for cases like this.
Now… most diff tools also have options to ignore whitespace changes, for cases like this.