I've Got A Little Song Here - S1-E12
Continuity mistake: When the others are cheering up Mike, there is nothing on the side. But a split second after Davy has left the room, the pad phone suddenly appears on the side so that Micky can call Bernard Class disguised as 'M.D'.
Answer: The Monkees TV series was very much a fantasy (this was the "groovy" psychedelic 60s, after all). Impossible things, such as items appearing out of nowhere, happened on their show without explanation all the time.
Jean G