In every corner of the apartment are colorful bits that inspire the Mary & Matt aesthetic, destined to be photographed for their blog. When I visited, the two had recently spent time in San Antonio during Fiesta, and they’d picked up this carton of cascarónes — dyed eggs filled with confetti — at the local H.E.B. (a Texas chain whose acronym stands for Here Everything’s Better.) “As a kid, I was obsessed with these,” says Matson. “Having a cascarón broken over your head is said to bring good luck.”