Thomas thinks his branch line is the most important part of the railway. Television producer Britt Allcroft agrees and renames his entire universe as "Thomas the Tank Engine & Friends".
Britt the Television Producer doesn't bother to read any of the stories or look at the illustrations, so she doesn't notice that Annie and Clarabel are bogie coaches instead of four-wheelers, or that Annie and Clarabel are private names that Thomas dreamt up. Britt the Television knows that children are Very Stupid and therefore cannot possibly distinguish Annie from Clarabel by the presence or absence of a guard's compartment, so she orders that their names be emblazoned on their sides in flowery cursive script.
Unfortunately Britt the Television does not understand this is like making a Superman TV series starring a double amputee who wears a jacket with the word "Superman" embroidered on it, instead of a wearing a red cape and blue tights.