System and IINA version:

• macOS 13.2.1
• IINA 1.3.1

Expected behavior:
IINA reduces animations if the user has enabled the macOS Reduce motion setting. From Apple's Human Interface Guidelines section Color and effects:

Play tightened animations when Reduce Motion is on. People can turn on Reduce Motion if they tend to get distracted or experience dizziness or nausea when viewing animations that include effects such as zooming, scaling, spinning, or peripheral motion. In response to this setting, you need to turn off or reduce animations that are known to cause problems (to learn more, see Responsive Design for Motion).

Actual behavior:
Entering and leaving the custom crop view uses a zooming animation.

Steps to reproduce:

• Click on System Settings… under the  menu
• Click on the Accessibility tab
• Click on Display
• Enable the Reduce motion setting
• Start IINA playing a video.
• Click on Crop > Custom… under the Video menu
• The crop view zooms into place
• Click on Cancel
• The view zooms away

• MPV does not have this problem.

How often does this happen?
Every time.