Preview-only controls
Display Adjustment changes how the editor presents decoded pictures for inspection. Brightness and contrast adjustments do not modify the source file or silently become export filters.
Rotation and aspect
Use View > Video Rotation to follow source metadata automatically or force 0, 90, 180 or 270 degrees. The preview and thumbnails preserve the effective display aspect ratio when the window changes size.
On-screen display
View > On Screen Display and Frame Number Display add navigation information for review. These overlays are editor aids and are not burned into a normal output unless a selected full-transcode/title workflow explicitly adds picture content.