The 'tiger step' is a classic Muay Thai cadence of advancing and retreating. Boxers, and kick boxers may label it as 'slow' and 'flat footed' which can be true/false depending on the lens you are evaluating it from.
Muay Thai fighters must be able to strike, and clinch; and strike from the clinch. Boxers and kick boxers don't which I think is the result of some of the disparity.
In any case, the cadence of the step actually resembles more of a wrestling/judo pace of movement simply because the Nak Muay must be ready to use leverage from the ground at a moments notice in a grappling scenario.
The mentality should be predatory in nature. Keep in mind, this is not to be confused as a 'blitzing' mentality. Predators like Tigers stalk, study and prepare for their prey. They know the prey can be deadly, and if not careful can be injured. As the saying goes, Rap ya nee, rook ya lap, 'When you advance, do not sleep. When you retreat do not run.'
In my opinion, Yodsanklai is the best at using sieu yam. He carefully stalks his opponents, applying steady pressure without over commitment and asserts himself when the opportunity presents itself. Even weight distribution in his steps allow for immediate advance, or retreat at the right moments. Watch the vid below and see if you see it too.
Yours in The Arts,