There has been some in-depth conversation about what such a feature could look like in this thread. There is some complexity both to making this accurate and performant in Collect and to avoiding confusion on the download side. Some folks involved in the user-facing conversation may be interested in engaging over there.
Others looking into this general topic may be interested in some of @Florian_May's suggestions in Tag/link pictures with defined field - #3 by Florian_May