"Looking from behind, my father's right shoulder looks like it's sitting lower than his left."
"Looking from behind, my father's right shoulder looks like it's sitting lower than his left."
"looking from behind" 「後ろから父を見てると」
"my father's ~" 「私の父の〜」
"right shoulder" 「右肩が」
"looks like ~" 「〜見える」
"it's sitting lower than ~” 「〜より下がっている」
"his left" 「彼の左の」