When reading the box, O'Gorman said, consumers will either rely on it or appreciate it was meaningless for the purposes of comparing protein attributes.
O'Gorman said the comparison being made on the cat biscuits created a "smoke and mirrors effect".
She said the method enabled Mars to label an "above average" product as the best.
"If the claim is highest then you are saying it is the supreme performing example and you can't make that kind of assertion comparing it to an average," the Nestle lawyer said.
O'Gorman said two of the Whiskas' varieties of biscuits, "Seafood Selections" and "Meaty", had a below average level of protein when compared to the average protein levels of Whiskas and Purina dry-food ranges.
These two varieties accounted for about 83 per cent of Whiskas dry-food sold, O'Gorman said.
Nestle is seeking both an interim injunction and summary judgment over whether the Whiskas products contains misleading claims.
The interim injunction would only be necessary if the summary judgement application failed and the matter required a more substantial hearing.
The hearing continues today.