The phrase "a big portrait" is correct and usable in written English.
It can be used to describe a large image or painting of a person or scene, often in a formal or artistic context.
Example: "The gallery featured a big portrait of the famous author, capturing the essence of his character."
Alternatives: "a large painting" or "an oversized portrait".
Before his death, he occupied his days with a big portrait of David Dawson, his devoted assistant and frequent model.
He and his family live in a comfortable house with a big portrait of their daughters on a mantle, in a well-maintained subdivision.
"You can either put up a big portrait of Stalin and note goldmining achievements, or you can put up death rates and haggard faces.
We eventually wandered up to 84th Avenue and sat down at Edgar's Café — I hadn't thought about the name and chose a corner table beneath a big portrait of Edgar Allen Poe.
And that sense of shock was clear from the way the paper dealt with the story, carrying a big portrait picture above a well-displayed panel recording his farewell statement to staff.
One relative, Ruslan Kuznetsov, with dark circles under his eyes, clutched a Russian tabloid featuring a big portrait of his older brother, 28-year-old Viktor, and an article about how their mother, just out of a hospital after major surgery, was waiting in Kursk for news of her son.
The painting by Merthyr Tydfil artist Steven Samuel is part of the Big Portrait Project, a collection of paintings of Welsh celebrities.
It wasn't going to be this big portrait of her as a person.
It's a big, loving portrait of a mottled bull calf, glowering at the viewer with an unsettlingly human mixture of defiance and hamburger-meat fatalism.
A big oil portrait of Colonel Qaddafi in flowing robes, sitting on a horse, was taken out of the mission's lobby.
HRC's first photo is a big posed portrait composed proudly only of "The women of Hillaryland in 2008"; who wants a one-gender world of any kind?
