typically interpretations of art are backed up with why someone looks at it that way. if it isn't backed up very well, people will reject that interpretation. this is why people can have different "readings" of books. for example, i could say that a red canvas signifies that the artist was trying to paint a heart, which is red, but messed up. this interpretation falls apart very quickly, perhaps because the artist painting the entire canvas red would be a very large mistake and highly unlikely. moreover, i'd have to justify why he was doing what he was doing in the first place with evidence (why he was painting a heart, or at least attempting to).

it's a good question and ultimately comes down to how plausible your interpretation is, but not necessarily philosophy. for example, in albert camus' "the stranger" we can see him make many references to how hot the sun is. we can conclude that this isn't here by mistake (we've found a pattern), and then maybe we can try to justify it and understand it in the context of the story (why does it matter?). the more your answer/interpretation is backed up by evidence the more people are willing to accept it.