Well it's a sort of room, and we expect you to make a lot of use of it.
Flowers bloom at most times of year, with a superb display of mesembryanthemums, from mid June to early August - that's the shimmering mauve flowers in the front wall.
But we suspect the favourite area will be 'Brett's Deck', that's the large decking area with relaxing seats, a table and sunshade. With the garden facing roughly westward, and with Scilly having very long/late sunny evenings (due to us being almost half-a-time-zone further west than London) you can relax and enjoy whatever is your favourite drink or snack, and also have a pleasant chat about the day you've had, or the days to come.
P.S. As to why it's 'Brett's Deck"' you'll have to read the story in our Visitors' Handbook that gives advice on Carn Ithen and the islands,