According to http://www.byond.com/docs/ref/info.html#/proc/browse_rsc browse_rsc() does not resend already cached data, however there is likely also a check to ensure that this data is up to date (using checksums or otherwise) or clients would only ever see the first photo they viewed in a given round.
This small change attempts to ensure that a given photo only has to be downloaded once by appending the photo id to the file name, reducing the risk of #7966 happening.
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