The company claims that photos will display as much as four times bigger on a large desktop monitor.
The changes to Facebook's photo-sharing interface suggest that the company is responding to growing competition from sites like Pinterest and Instagram and from Google+, which includes a full-screen photo viewer, according to Patrick Moorhead, the principal analyst at Moor Insights & Strategy.
"This is absolutely a defensive move to thwart off any advances that either Instagram or Pinterest will make," Moorhead said. User appreciate how Google+ handles photographs, he said.
Some social media enthusiasts are spending less time on Facebook and more on Instagram and Pinterest, he said.
Facebook did not immediately respond to a request for comment.