You can drag&drop onto a link by clicking the link itself to make it active, then you can drag the attachment to the grey area above the "Notes" tab.
Thanks, but I was aware of this option.
Allowing users to drag&drop directly onto the link may cause a lot of confusion for users that intend to drag&drop the attachment to a thought but end up attaching it to a link instead.
If this would cause confusion, could be decided by some usalbility tests. This is no different from the current situation. When a document is added to a brain by drag&drop, is it added as an attachment to a thought or is it linked to the active thought? Right now, the (sensible!) solution is to highlight the thought (by displaying its border) if the document would be become an attachment. A simillar highlighting technique could be used to mark the link as the drag&drop target. In fact, such a technique is already in place. A link is highlighted when the mouse cursor points to it.
Reinhard, TB 126.96.36.199, WIN 10
Quality is the result of attention paid to details.