Photoshopping label onto graph
My interpretation of the question is:  


  I was told it is unethical to photoshop my data.  Is it ethical to use Photoshop software to make a graph?


The choice of software used is completely irrelevant to the ethics of any scientific image.  You can use python, Photoshop, or crayon.  If the image is drawn correctly, it is okay.

If the contents of the image is false, that is never okay.  It is much worse if it is deliberately false.  When people say it is unethical to photoshop, they mean that it is unethical to lie.  They do not mean you cannot make truthful images using the Photoshop brand software.