What does the 'Camera' category in Geekbench 4 refer to?
https://www.geekbench.com/doc/geekbench4-cpu-workloads.pdf 
Try going to that PDF. It's from Geekbench themselves and they explain the different methods of each workload. 
In this case, Geekbench processes photos rather than take them. It applies filters etc. and decrypts, compresses etc. 
From that PDF:


  Camera replicates a photo sharing application like Instagram. Camera merges several
  steps into one workload 
  * AES decryption 
  * AES key generation using PBKDF HMAC SHA1 
  * SHA2 checksum generation 
  * JSON parsing 
  * JPEG compression and decompression 
  * PNG decompression 
  * Image compositing 
  * Image filters (gaussian blur, contrast) 
  * SQLite (INSERT the processed image metadata into a database) 
  All steps run on the CPU and are not accelerated by the GPU.