Large Square Picture on Desktop

[jamesadrian]

I use MagicJack only to call out. I do not want it on my desktop unless I click on the "Open magicjack" icon. How can this be done?

I am using an iMac computer.

A large square picture appears on my desktop in a place I cannot control whenever I turn on my computer. I don't want it to appear.

Thank you for your help.