Discussing with Tom Beament the fourth feature of intentionality in the Brentano-Molnar approach. Physical intentionality requires ice and liquid water to be taken as two modes of presentation - or an apple and an apple pill with all of its chemical components. Tom argues that in cases of (non-physical) intentionality, differences in modes of presentation - take Hesperus-Phosphorus and Superman-Clark Kent as the typical examples - have nothing to do with what can be described in terms of the directed object. It is not a physical difference, I think he wants to say.
I'm convinced that it is enough, for Molnar to have his way about a significant similarity between Brentano's features of intentionality and his physical intentionality, that at least some cases of differences in modes of presentation can be understood in terms akin to those used in the examples of physical intentionality (say the ice example or the apple pill example). That is to say, at least in some cases, differences in mode of presentation in (non-physical) intentionality are about differences in the physics of the objects being presented.
I believe there should be always differences between things in order for them to be considered different in mode of presentation. It is a matter of a matrix of differences and indifferences. Any difference in mode of presentation is supervenient on physical differences - or on differences that follow from the matrix. So, Hesperus is perceived as a star that appears in the evening - it is in fact present in the sky in the evening. It is different from Phosphorus that appear with other morning stars and morning events. Analogously, there are physical differences between the appearances of the superman and that of Clark Kent. Surely, the horse qua horse is not what attracts a tick, but rather the horse qua mammal. This, however, implies no more than there are indifferences as part of the matrix - horse or cow, that doesn't matter for the tick. If it mattered, the tick would be able to distinguish between them. Sugar dissolves in water, and the water that dissolves it has to be in the liquid state to fit the sugar's dispositional bill. Being liquid - or appearing in the morning or wearing a shiny blue overall - supervenes on something physical.