These are the "Quick Actions"—the buttons that appear over an image (the padlock, the heart, the share icon, etc.).
The solution you’re looking for is already right there in your screenshot:
Look at the first button in the top-right corner: the padlock 🔒. This is what allows you to disable (and re-enable) pinch-to-zoom!
When you open an image in Aves:
- Tap the image to make the buttons appear.
- Tap the padlock 🔒—the image will then be locked, preventing it from being zoomed in via a pinch gesture.
- If you want to re-enable zooming, simply tap the padlock again; you’ll then be able to zoom in on the image as usual.
This is exactly what you need: you can use the padlock to disable zooming whenever necessary, and turn it back on whenever you like.
Don’t bother looking for a "pinch" option in the settings; Aves doesn’t offer a permanent disable setting, but rather uses this padlock as a quick toggle (ON/OFF switch).