While using ArcGIS Pro in the Attributes Pane there are the three tabs Attributes, Geometry, and Attachments. I think it would be a good idea on the tab list for the Attachments tab to show an indicator that there are attachments. A count would be better, but some kind of indicator would be great.
Typically when I'm editing data or even view attributes on selected features I like to have the Attributes Pane up and docked and I use it mostly on the Attributes tab. Some of our data has attachments and some does not. It would be very helpful if just at quick glance it could show that there are attachments, that way you know to check the attachment tab for further information. My idea would just to show parenthesis with the number of attachments, so it would show: Attributes | Geometry | Attachments (2) - meaning that particular feature has two attachments. ArcMap does this in it's Attribute window. Can you bring it over to Pro?