Emma Ridgard told Leeds Crown Court she had been cleaning and pricing a watch display in the window of the Albion Street store before three robbers came in the shop just after 3pm on March 24.
Mrs Ridgard said: “He got the gun out of the bag and then he shouted ‘get down’.”
Mrs Ridgard said she started crawling to the other side of the shop after one of the robbers started moving towards the watch window.
Prosecutor Timothy Capstick asked her: “Did people get down?”
Mrs Ridgard replied: “Yes, we all got down, apart from my boss Jeffery (Walton) who stayed stood up.”
Mr Capstick asked her: “How did you feel?”
Mrs Ridgard replied: “Very afraid.”
Mr Capstick asked: “What did you think might happen?”
Fighting back tears, Mrs Ridgard said: “I was very scared, probably as scared as I’ve be in my life.”
High value watches, including Cartier, Patek and IWC watches, worth more than £900,000 were stolen.
A total of 64 watches worth £485,505 were recovered, but watches worth more than £455,000 are still outstanding.
Four men are standing trial charged with conspiring to rob Berry’s on March 24 and Watches of Switzerland on Oxford Street, London, on February 25 this year.
Estonian nationals Raigo Malm, 39, Alar Kajurand, 26, Rainis Kilk, 26, and Tamair Uibopuu, 30, all deny conspiracy to rob.
Berry’s sales assistant Ellen Anderson told the court she also crawled away from the watch window to the other side of the shop during the robbery.
She said: “I have been in the shop before when there has been a robbery and it’s been for watches that they have come for.
“I said to Emma ‘we need to get away from the window,’ so we crawled across the floor to the opposite side.”
Mrs Anderson said she saw one of the robbers taking watches out of the window.
Prosecutor, Timothy Capstick asked her: “How were you feeling?”
Mrs Anderson replied: “Really shaken up. My hands were shaking. I couldn’t stop shaking when it was happening.”
Sales assistant Karen Gilling said she was walking down stairs from the first floor carrying a pot of tea when the robbers entered the shop.
She said she got to the bottom of the stairs, looked from behind a door and saw a man holding a gun.
She told the court: “There is a cupboard with a bi-fold door on it. I was so frightened I tried to hide in the cupboard.”
The jury has been told watches were taken from window displays, which were not locked.
Berry’s president Jeffrey Walton has previously told the jury a suggestion by Kajurand’s lawyer David Dixon that the armed robbery was staged for insurance purposes was “ridiculous.”
Mr Walton said he had been involved with Berry’s for around 49 years and that there had been around four previous armed robberies.
Prosecutor Timothy Capstick has previously told the jury that Kajurand was caught on CCTV wearing a wig and a hat as he approached the locked security door at Berry’s.
The jury was told Kajurand produced a gun once he was allowed inside by the security guard.
Mr Capstick has said Kilk and Uibopuu then entered the store armed with hammers before taking watches.
Mr Capstick said that after the robbery, Kajurand and Kilk ran down Albion Street and caught a train back to Manchester from Leeds rail station.
The jury has been shown CCTV footage of members of the public detaining Uibopuu on Albion Street.
A hammer was recovered from a bag, along with 64 watches that had a combined value of £485,505.
The jury has been told that in the days leading up to the robbery in Leeds, all four defendants were staying at the Britannia Hotel in Manchester.
Mr Capstick said Kajurand and Malm travelled to Liverpool on March 22 to buy a BB gun or air pistol from a shop in the Anfield area for £50.
The jury was told the two men disposed of a bag containing the gun and wig in industrial bins in a side street in Manchester, which was later recovered by police.
Mr Capstick said Kajurand can be linked to the wig by DNA and to the gun by a fingerprint found on the grip of the weapon.
Police arrested Kajurand and Kilk at the Brittania Hotel in Manchester in the early hours the morning after the robbery in Leeds.
Mr Capstick said Malm was not present at either of the robberies, but was involved in planning both raids.
He told the jury that while Uibopuu was involved in the armed robbery in Leeds, there is no evidence to suggest he was involved in the armed robbery in London,
The court heard six Cartier watches worth just under £30,000 were stolen during the robbery in London.