This is a pretty grim painting, very dark and macabre. One has to take time to look at it and decrypt its symbolism, this blog post has an excellent dive into it. Check the scale for details:
"the two trays of the balance are labeled in Spanish: Nimas & Nimenos, or Neither More Nor Less. Nimas, at left, weighs animals that represent the deadly sins: a peacock for vanity, a dog for anger, a goat for avarice/greed, a monkey for lust, a hog for gluttony, a sloth for laziness (or sloth, ha, ha, ha), and a bat perched on a human heart for envy. “Nothing more [than these] is needed for damnation.”The other piece is pretty grim too, called "In the Blink of an Eye" (In Ictu Oculi) where a skeleton pinches the flame off of a candle reminding us about the shortness of life and its quick disappearance.This piece is full of symbolism too, like how the skeleton has his foot on the globe!
There is also a "urban legend" related to the founder of the hospital and the church, Miguel Mañara, allegedly being the origin of the legend of Don Juan, which probably wasn't the case, but makes an interesting anecdote!
What's interesting to know is that at the time of Miguel Manara, Seville was going through a big decline. Apparently, at the time, it was "fashionable" for nobel men to set up a hospital and tend the poor. There are many such big hospitals around the town, for example, the current parliament and the Fine arts museum building.
This sentnce describes the mood well:
In Seville, the popular riots of 1642, the Black Death of 1649, the drought of 1682 along with the floods of 1683 caused the disappearance of a large amount of population as well as the gradual weakening of its social and economic structure.