Can you tell me the difference between the above two? The aesthetic difference is betweenて andた only.

テレビを見てからケーキを焼きます means “After I watch TV, I will bake a cake” while
テレビを見たからケーキを焼きます means “As I watched TV, I will bake a cake.” Probably the writer was inspired by a cooking programme on TV, so she decided to bake a cake!

Remember: てform + から states the sequence of events. The plain past form + から indicates the reason or cause.