If we look to the analysis of the first four songs, then one thing is very obvious. The first and third songs are dynamic in character, while the second and fourth song are static. Song 5 is rather dynamic again, and resembles in a lot of aspects song 1. The start of the song is more or less like that in song 1 with one single tone before the first bar
Poem 5, like poems 1 and 3, is about the wonderful aspects of love. It is about dreaming of the lily that should sing a song of the beloved as the kiss she once gave. So, again, the meaning is not as optimistic as the surface level suggests.
The harmony starts in b minor, with IV-V7-I (m1-2), repeated in m. 4-5. The second two lines provide a different development. The bes in the piano arpeggio makes the e minor chord diminished, while the e minor then develops to A7, D7, G7, C7, all with sharp sevenths. The second chord in m. 7 seems not to be clearly defined, and in the second half we have a Cis7 that develops to b through Fis7 in m. 8.
The second strophe is a repetition of the first till m. 15. Then it develops much faster towards b minor. The piano postlude remains first in b (with Fis7, e chords with diminished chords in between. M. 19 shows a short development through Cis, with the ais and d in the second chord not clearly defined, but then Cis-fis-b. The end is just repeating b with its dominant, but as a minor chord. This may suggest ecstasy followed by dreaming after "In wunderbar süsser Stund".