The ending of Blowup

I've just finished watching a movie by Antonioni called Blowup and it has one of the most random endings ever. However, here's my interpretation:

The whole movie is a character study of this self-absorbed, talented photographer who is childlike only because he's an Artiste and commanding. He's always in his own world. He's the type who plays around with women for power and who would do anything to get what everybody else wants (like the guitar neck) even if it means nothing to him. When he discovers a murder, he's the type that would never even consider going to the police. Instead he goes to his publisher-person and says, "Look what I've got!" almost bragging but doesn't photograph it. Only after bragging does he go to photograph the body and then it's too late. He would photograph the body because it'd be a nice 'addition' to all the brutality that's already in his anthology.

So he goes to the park prepared to photograph the body but finds that it isn't there. For the first time, he senses a loss, as if the murder had never happened and he had been imagining it. The mimes then show up and fills in that sense of loss with another type of imagination, replacing the negative image of a lost body with a positive image of an imaginary ball and tennis match.

The protagonist is worlds away from the university students and activist types. Although he is an artist, he seems not to care for amateurs (he doesn't give the fans a chance and he only permits the girl to put the NO BOMBS sign in his car because he finds it highly amusing).

He is a photographer, and they are theatre-mimes. Photography highly depends on the visual and the concept of presence - what is there. However, mimery is a performance art that is ethereal and depends on the mind to fill in the blanks of what is not there.

So when they start 'playing' tennis he is amused, but when he is asked to pick up and throw back the imaginary ball for them he crosses a boundary - he becomes part of their world and breaks the bubble of self-absorption. He is forced to participate in the world that is greater than himself, a world dependent on negative visual presence while he is so used to positive visual presence.

This is a good ending because all the events that have happened up until the end - the photography, the murder, the party, the coming back for photographing the body - lead him up to crossing that boundary that is a complete character. By the end of that scene and therefore by the end of that movie he has changed himself, if only for a second.