KENNEBUNKPORT, Maine - George H.W. Bush is looking healthy and happy in a new photo from his hospital room shared on Twitter Friday.

The former President tweeted about reminiscing on life while reading his granddaughter Ellie's book.

The tweet read: "Enjoying a great book and a wonderful walk down memory lane this morning. Yet another reminder of just how lucky I have been in life. Very proud of the author and co-author too."

The new book is titled "George and Barbara Bush: A great American love story."

According to the website, it "paints the portrait of the enduring relationship of George and Barbara Bush. Sharing intimate interviews with the Bushes and family friends, this is a never-before-seen look into the private life of a very public couple."

The book is the first published work from Ellie LeBlond Sosa and it was co-authored by Kelly Anne Chase, a a New England-based writer and magazine editor.

The former President was taken to the hospital on Sunday after experiencing low blood pressure and fatigue.

Jim McGrath, Bush's spokesperson, says he will likely remain in there for the next several days for observation.