Sometimes the drop target is within a set of linearly arranged objects. After the item is dropped, objects following the drop target will move to make space for the new object. In that case, the insertion point is typically indicated by a thin line between the two objects that will separate to make space.
For example, in almost any GUI that uses a mouse, text can be selected and dragged from one part of a document to another. The insertion point is indicated by a thin line between two characters.
That's also the case with the Netflix queue discussed earlier. In addition to a thin line, Netflix uses a black arrow to indicate where the movie will go.
Thundercats: Season 1: Vol. 1: Disc 3
.....................................
Thundercats: Season 1: Vol. 1: Disc 4
>-------------------------------------
Thundercats: Season 1: Vol. 1: Disc 5
.....................................
Thundercats: Season 1: Vol. 1: Disc 6
(I can't figure out how to grab a screenshot while dragging.)