Break it down into its basic elements. What do we got? Mountains, clouds, field, water, sky.
What are the simple descriptions we can use that will immediately get across this concept in the least amount of words possible? Snow-capped mountains. Drifting clouds. Clear skies. Flowering fields. Pristine lake.
Character looked out and saw flowering fields, broken up by the mirror surface of a pristine lake. Fluffy clouds drifted below clear skies, close enough that it seemed like Character could reach out and touch them. Snow-capped mountains bordered the horizon.
If you want, you can then throw in some sensory information to round it out. What’s the air like, what’s the temperature, can one hear the wind blowing through the grass, or birds singing, etc, etc. You don’t want the reader to feel like they’re looking at a picture, you want them to feel like they’re standing in it, so sensory information is usually better at getting that across. If it doesn’t matter to the story how many mountain peaks are in the distance, then leave that to the reader’s imagination. What you really want is for your words to evoke the same feeling that the picture does.
And style, obviously, can come into play, and make things more flowery, or less. To add in more details, just lengthen the list of elements you want to describe, like including more about the flowers or grass or distant hills or visible greenery on the mountains, and go from there.