Upvote:3
Even if other vaccines can be recorded in it, the main use for the International Certificate of Vaccination or Prophylaxis is indeed checking whether you have been vaccinated against yellow fever. This requirement is not mainly about keeping you safe. Rather, it's designed to prevent spreading the disease in places that are at risk of local transmission.
I have heard about people getting away with a lot (including not being vaccinated) but I would not assume a picture of the document is enough. The Wikipedia article mentions newer digital versions used in some countries but that would be specific to those countries, the only standard document is the physical booklet (it's often called a card but it's closer to a passport).
What vaccines are recommended or beneficial for you is a completely separate question.