Let's examine this guy's stance:
Ahh, look; those nice old ladies just wanted to get a cool picture practicing Tai Chi in front of The Leaning Tower of Pisa and some big Goof pulls some Karate on them!
Even a structure as strong as The Leaning Tower of Pisa can have faults in it's foundation that may eventually bring it down. The old ladies are in a transition between movements in the picture, and they appear to be armchair martial artists, so I'll give them a break.
But let's look at the stance of the Karate guy.
This is definitely "old school". His lead fist is held palm up, it appears with extended knuckle (phoenix-eye fist). His rear hand is slightly forward and not in deep chamber, that is fine but it is held pretty high.
While he has more weight on the lead leg I would consider this a "double-weighted" stance. It is also extremely wide, preventing mobility. In order to move quickly, he must shift completely to one leg or the other. This is the kind of stance where you can basically only stand there and trade punches. It is so deep I think he might have trouble firing off a front kick with either leg, and his knee looks like a perfect target for a stomp or arcing round kick.
San Ti Stance From Xingyi
The above stance is also very old-school, but observe the difference in mobility. It is not as wide, the rear leg is slightly bent and spring-loaded. The practitioner can take a load into the root of the stance as well as discharge power back; borrowing the opponent's energy. The rear hand is ready to protect against a groin kick.
Yang Chen-Fu in "Raise Hands"
And here's another good stance for mobility, from the Yang-style Tai Chi Chuan system. Hands are held relatively high, lead leg ready to kick, very mobile.
- My preference is somewhere between the second two stances. In the Xingyi San Ti I can take a load in push-hands as well as move and hit. If the opponent closes I can cover with the "boxers triangle" or "shaving" type neutralization.
Good stuff, it works for me.