jpg image processing drops query string parms.

I noticed that for this URL:

WPT actually evaluates (notice the last dropped query string params)

It looks as if the analysis always truncates after the first query string key/value pair, yielding incorrect results. Is this a known issue?

You need to urlencode the image URL (all query params in general). The URL for analysis should be:

Pat, you are correct, it was an oversight on my part. Thank you for your prompt response.