Answer:
vividly informative and helpful
Explanation:
Instructive refers to something that is vividly informative and helpful to the viewer. The meaning of this word can be determined in this scenario through what the self-portraits provide. They provide a vivid representation of the artist and how he sees himself, therefore enhancing all of the little insecurities or features that they may be very proud of. It also shows the features that the artist wishes to have or how they want to be seen which is extremely helpful in highlighting these features.
The word "felicity" in this context means happiness, since the character managed to reach an state of almost ecstasy after finding happiness in his prayer, being thankful for what was happening. In this passage, the character uses the word "felicity" as a synonym of profound happiness.