Usher recently attended Art Basel, an international art show in Miami Beach. While at the art show the singer visited the Vector Gallery's “Body As Commodity” performance and art installation.
The installation consisted of a model, Lena Marquise, acting as a human iPhone charger. Phones were connected to a battery pack Marquise had inserted inside herself.
Usher decided to take Marquise up on the offer and paid $20 for 10 minutes of battery life. The gallery described the symbolism behind the performance on their Tumblr:
"Body As Commodity" forces the active audience to consider whether using a doll for sexual pleasure commodifies sex more or less immorally than using a real body for amenities that can be monetarily quantified, such as energy; the charging of a mobile phone. This performance piece uses the exchange of literal energy (battery life) for figurative energy (use of a body) at a monetary expense to exemplify the exchange of simulated sexuality for monetary gain.
Marquise told TMZ that she could have taken two phones at the same time if need be. She also had a battery pack that supported Android, in case you were wondering.