Each source attached to a person could indicate whether there is an Image for it.
Comments
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Each source is treated as a separate record by FamilySearch. There is no way of the system "knowing" if there is an "image only" record (matching an indexed record) somewhere on the website. If an image is available via an indexed record this should already be accessible by the means you suggest.
To clarify, I often get a "No image available" message when I examine a source, but this is not necessarily the case due to the many, separate image-only collections on the website. Without them being indexed there is no way the "system" has any record of them, so it requires the user's efforts to discover them.
If there is a direct link to an image from an indexed record I believe there generally already is a "camera" icon alongside the source on the familysearch.org Results page. (See https://www.familysearch.org/search/record/results?q.givenName=john&q.givenName.exact=on&q.surname=wrightson&q.surname.exact=on&q.birthLikePlace=united%20states&q.birthLikePlace.exact=on&q.birthLikeDate.from=1860&q.birthLikeDate.to=1910&count=20&offset=0&m.defaultFacets=on&m.queryRequireDefault=on&m.facetNestCollectionInCategory=on for examples.
As far as ascertaining whether an image is available after the source has been attached, see https://www.familysearch.org/tree/person/sources/G456-1R6, where one click (to open the source details) will reveal if there is an image.
Please explain if what you are suggesting is not covered (in the examples shown above) by the type of sources / indicators to which you are referring in making this request.
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