Not to take this cartoon at face value (for obvious reasons), but there is actually a gem of an advice lurking in this funny picture. Even though it's clearly satirized here, the concept does work - and you should keep this in mind whenever you realize you're feeling depressed or anxious out of the blue. Change your surroundings! Well, don't just change your surroundings like in the cartoon here... make sure to go somewhere that makes you feel better inside: that is the key to making this advice work.
As general rule, find a place that contrasts your current location - if you're indoors go outdoors, if you're in a well-lit place try stepping into the shade, if you're alone get some company, if you're in a hectic place find some solitude. But all the while, pay attention to how a place makes you feel, and find somewhere that makes you feel comfortable. It may sound too simple to be effective, but this advice will help you crawl out from that dark hole where depression keeps trying to sink you into.
Remember, you don't have to be a victim of depression... unless you make that choice. And you can always choose differently at any given moment, and usually you enact the right to choose by taking some kind of action.