You ask a very astute question that could take many, many pages to answer completely. Since I do not know your level of interest or the details of your experience, I will try to give just a basic answer. Others may well disagree with what I say.
The names you cite are not part of the Yang Style tradition (or any other I am familiar with) and so it is difficult to respond to your question with any certainty.
If your teacher claims to be teaching Yang Style, I could speculate that your teacher has renamed moves 2 through 4 of the traditional form (see elsewhere on this site, under Tai Chi Info), using names he or she thinks would be less intimidating or more evocative than the traditional names. If I am correct about this, spending an hour to learn and practice these moves would not be unusual for a beginning class, or even some advanced classes.
Another possibility is that your teacher is teaching isolated postures or Qi Gong moves meant either to give you a feel for Taijiquan or to allow you to practice basic types of movement. This type of approach seems to be reasonably common among teachers that are less traditional in their approach. Spending an hour doing this would probably not be so common, but still would not be considered as strange as it would be in a Karate class.
Although some see Taijiquan and Karate as being simply different approaches to developing the same martial skills, I think that there are profound differences between the two that benefit best from quite different training, teaching, and study methods.
It is often said that arts like Karate favor training from the outside in, while arts like Taijiquan favor training from the inside out. This means that the purpose of practicing movements and the principles that they express is often quite different, even when there is an external resemblance. Although Taijiquan has punches and kicks, these are generally not useful units for studying or even discussing the basics of Taijiquan.
I hope this helps.