At least one instance of using pictures to illustrate things.

Your quote is about being opposed to weak (informal, hard to show correctness or make consistent across the range of things he wanted to prove) proofs by diagramming, where he wanted more formal reasoning.

The man was no fool, in at least some of his presentations I've seen (videos) he also used diagrams and pictures to illustrate things. They're necessary on occasion.

EDIT: Typos from trying to comment from my phone.