to pile up
- to exaggerate (a story)
- to beautify (one’s appearance in a photo)
Originally, 盛る is often used in the phrase ご飯を盛る meaning “fill/pile up rice in a bowl” or 土を盛る meaning “pile up sand”. Figuratively, it means to exaggerate a story by adding extra (unreal) details to it.
It also means “to beautify one’s appearance in a photo (e.g. using photo-editing software or fine-tuning the best angle)”, and 盛れてる写真 means a photo where one looks better than usual.
Hey, look! I look really nice in this photo!
He always exaggerates stories.