thumbnails in portfolio

please help to understand
how to create thumbnails in portfolio
i want thumbnails below feature image

i tried by ” add media then create gallery but images are coming on side

have a look on below link for better understanding
https://customusb.in/portfolio_item/business-credit-card-usb-pen-drive/

i want how we have gallery in posts or pages, have a look on below link
https://customusb.in/car-charger/

thanks
Jitendra

• This topic was modified 8 years, 3 months ago by subusb. Reason: added more details for better understanding
• This topic was modified 8 years, 3 months ago by Andrew Nevins.