Tone is the overall impression the reader is left with. If I decide to describe the 45 minute bus ride from Iceland's Keflavik airport to the capital city of Reykjavik, I could try for laughs because it has to be the ugliest landscape in the world outside of North Jersey. The first time traveller to Iceland cannot help but think, "OMG, this was a BIG mistake!"
I could go for quiet and somber to describe a vista of gray lava that in historic times rained redhot out of nearby volcanoes and destroyed lives, animals, farms, and livings.
I could avoid both humor and the dark stuff and pique the reader's curiosity by describing the little details of the trip that seem very alien to an American's eyes: the wrecked car monument: the horse tracks along the four lane highway; the toy pedestrian and bike bridges over the traffic; the obvious lack of need for the massive foundations our winter frost necessitates.
I could shoot for outrage and anger. The US Naval Air Station in Keflavik is closed now, but the town somehow manages to combine the worst and ugliest features of both the USA and Iceland. It's embarrassing, painful, shameful.
In each case, it's the same bus ride over the same blasted landscape, but the writer dictates where the piece goes and how it affects the reader. That 'affect' is the tone.
By the way, tones can be mixed. Here's what Edmund Gosse has to say as he introduces his book about his relationship with his father: "There was an extraordinary mixture of comedy and tragedy in the situation which is here described, and those who are affected by the pathos of it will not need to have it explained to them that the comedy was superficial and the tragedy essential."
As far as what 'travel' means, I leave that to you. It could be your daily commute. It could be a visit to grandma's. It could be a shopping expedition. It could be around the world in 80 days. I wrote my piece for 262 about my summer trip to Iceland.