I always change "X represents Y" to "X is Y" in technical papers unless X is a symbol If X is the mean value of three independently run experiments on three separate groups of rats, then I change it to "X is the mean of three independently run experiments". The pretentious phrase "X represents Y" is very, very common in biomedical papers.
The usage is common because academic writers imitate what is published on the assumption that if it's published, it must be good English, especially if it's been written by a native English-speaker. Trouble is that it's not always possible to tell whether the first author is a native speaker of English & not always good writing even if it's been written by a native English-speaker & copy-edited by a native English-speaker.
If you're a poet or a painter or a composer, for example, you can give someone one of your representative (typical) opuses and say that "This is representative of my best work these past few months", but not, except very informally, "This represents my best work these past few months". The proper usage is: "This is John. He's my lawyer. He represents me in civil suits" and "This is a voodoo doll. It represents the person you want to put a curse on".
Google NGRAMS viewer shows no hits for "This represents my best", and a normal Google search shows that most sentences with represents talk about symbols or agents (e.g., lawyer or power of attorney).
If, as one hit says, "Please note this represents my 'best guess' on when they would do it", it should be "Please note that this is my 'best guess' on when they would do it".
