Nope, there's no pictures, and no sex, either. That's what sweet / clean romances are. But truly, that's all there is to it. No detailed, "pink parts" (as I saw one small press company state) scenes. There can be light petting, kissing, and light making out. But the idea is, it doesn't make you blush while you read it.
But sweet / clean romances are still very much written for women, not children. The relationships, which drive the story, are deep and tender. Sweet romances are usually looked at as being a sweet, falling in love story between two people, with obstacles, but they are usually about the freshness and excitement of falling in love with someone, and how the relationship develops. Sweet romances are usually not dark stories.
A clean romance is looked at as being a little different. There is still no explicit sex, but the plot is generally darker, and therefore, the author doesn't feel the "sweet" label fits.
An inspirational is a novel that is faith-based fiction. To be faith-based, the novel must have the values of that faith. One way to look at it is this: An inspirational novel is always sweet, a sweet / clean romance is not always an inspirational.
But mostly, the sweet / clean label is used almost interchangeably. What you can be sure of is that when you pick up one of these books, you'll swept away by emotions. And when you come to the end of the story, you'll feel good about what you just read, and want to start all over.