I pulled this pair of cards and the meaning seems to be 'eventual success' or as LearnLenormand.com says:
Mountain + sun (31): success finally occurs
The reverse order meaning is pretty funny. I had to laugh considering my daughter is named for a volcano:
Sun + mountain (21): delayed success, volcano
I guess this is generally good--although Mountain does represent a slow change, something taking a long time to come to fruition. I guess my patience and letting go cards of late will have to be applied in this case.