It was to show Gazans' solidarity with Arabs in the West Bank, because they know that checkpoints are so terrible.
After all, Gazams may have it bad, but at least they never have to physically see a Jew in person.
The protest also was to call to boycott HP, for providing technology to Israel that, they claim, is used to oppress their West Bank cousins.
Of course, all good street theater must provide some drama and violence.
I'm sure the people who live in mansions in Ramallah appreciate being thought of.