Imagine one is encouraged by friends and institutions for their 'different' artistic or other activities, even if their works are not along the lines of 'acceptable' norms and tradition.

along 在这里表示"沿着...方向"，引申为"符合某种标准或模式"。 the 是定冠词，特指后面提到的"lines"。 lines 原意是"线条"，这里引申为"标准、规范"的比喻表达。 of 表示所属关系，连接"lines"和"norms and tradition"。 along the lines of 这个短语整体意思是"符合...的标准/规范"，表示与某种既定模式或传统相一致。