How do I limit Gmails access to my phones contact info, specifically pictures?
Your phone and your Gmail contacts get synced, which means if you change a contact on your phone, it will change on your Gmail contacts too, and vice-versa. It is not a one-way deal.

To limit Gmail access, you will have to disable contacts sync entirely with Gmail(using the slider) in the settings app.

Your contacts include pictures as information which is part of the contact, and Gmail syncs the entire contact, so there is no way to block Gmail from accessing your contact photos.