Hello viplesh,
For information about the technical specifications for iPhone 12 mini, and the camera, please check out the details in this link: iPhone 12 mini - Technical Specifications
Camera
• Dual 12MP camera system: Wide and Ultra Wide cameras
• Wide: ƒ/1.6 aperture
• Ultra Wide: ƒ/2.4 aperture and 120° field of view
• 2x optical zoom out
• Digital zoom up to 5x
• Portrait mode with advanced bokeh and Depth Control
• Portrait Lighting with six effects (Natural, Studio, Contour, Stage, Stage Mono, High-Key Mono)
• Optical image stabilization (Wide)
• Seven‑element lens (Wide); five‑element lens (Ultra Wide)
• True Tone flash with Slow Sync
• Panorama (up to 63MP)
• Sapphire crystal lens cover
• 100% Focus Pixels (Wide)
• Night mode
• Deep Fusion
• Smart HDR 3
• Wide color capture for photos and Live Photos
• Lens correction (Ultra Wide)
• Advanced red‑eye correction
• Auto image stabilization
• Burst mode
• Photo geotagging
• Image formats captured: HEIF and JPEG
To help us better assist you, can you confirm if the photos you're noticing this with were taken on your device directly, in the Apple Camera app? That information will help us get a better understanding of the situation.
Thanks!