A location can carry a flat Main image, a 360° photo, or both. When both are set the 360 wins the card's photo slot, so this really comes down to which one tells the story better.
Reach for a flat photo when
One clear subject says it all. A shopfront, a product, a plated dish or a headshot reads instantly as a still. There is nothing to look around at, so a crisp flat photo is the stronger choice.
You want control over the framing. A flat image shows exactly what you composed, every time, on every device. Nothing shifts as the visitor drags.
You have lots of locations to fill. Flat photos are quick to shoot and easy to source, so a big directory stays consistent without much effort.
Reach for a 360 photo when
The space is the point. A room, a venue, a stand, a viewpoint or anywhere the feeling of being there matters. Letting visitors look around sells a space in a way a single frame cannot.
There is more than one thing to see. If a single photo would have to leave things out, a 360 lets people find them for themselves.
You can capture it well. A 360 rewards a level tripod, even light and a high resolution shot. See Take 360 photos that look good on your map.
You can keep both
Setting both is a useful safety net. The 360 shows on the card, and if you ever clear it, the card falls straight back to your flat Main image rather than going blank. It is a low cost way to hedge while you gather 360 shots for your best locations first.