I'm not positive that's her. Her face isn't visible in either photo. Are you sure she didn't just have a friend pose for the pictures?
I don't think that's her either, for the same reason you mentioned.
If it was Gates, we would actually see her face.
BTW that gym scene is described by both Gates and Marina as sexistic. And I agree: It was too on the nose with the posing and the mirrors. When I saw it it felt very creepy.
That's interesting since my focus was more on the costumes both her and Sirtis were wearing; I thought the costumes both her and Sirtis wore were very...fugly.
As I mentioned in another thread, the Berman-era became very conservative, very rigid.
One of the main complaints I had was that feminity was being stripped from the show. For example, no costumes should show skin especially on the women, no female should show any vulnerability (e.g. this trickled down to Kira Nyrys (sp?) from DS9) since that is showing weakness.
(Note: Many of the male costumes, I thought were pretty conservative and ugly as well).
With that said, the funny thing is: While Troi definitely looked good in the season 1 skirt and boots, the idea of a counselor and how her character was portrayed makes sense that she would be in the blue dress she later wore. (Although, there was yet
another complaint that there was a plunging neckline!)
I find this an interesting contrast to 1. Jadzia Dax, who was seen in a towel at one point in the show, comfortable with her sexuality, and was a formidable fighter. Granted, she would be kinda mean to Odo, based on SFDebris' comments....but Jadzia was tough. Yet, she's not seen as a 'strong' character by some, or as strong as Major Kira.
2. Ro Laren. I thought it was refreshing to have a character who shook things up with the TNG crew, who all came off like a clique who did everything by the book (or when the 'book' suited their purposes). She was her own person, yes angry at times, even mean to people who tried to get to know her (I'm going off my vague memory since I haven't seen her episodes in years)...but she kept to her guns.
3. Tasha Yar actually was in the skirt and boots in the second part of 'Encounter at Farpoint,' albeit that damn console she worked at pretty much hid her from audience view. She also showed skin, she was tough sometimes a bit too impulsive, she showed vulnerability...yet, she was killed off. Yeah, the actress wanted out but why couldn't she had transferred to another ship for a time? Stuck in a sort of Nexus, filled with 'joy' until they wanted to bring her back?
Another character who I want to mention is The Intendant from DS9; Kira's double. The Intendant was dressed in tight leather, was bisexual, was double-crossing, was sometimes hammy.
Yet, I find her cool. Yeah, her outfit was interesting but you never knew what this character was going to do since she was always out for herself.
Lastly, to close off this little essay

, I don't think it would have demeaned Crusher if (off duty, although a Doctor is technically always on-duty) we see the character in a season 1 skirt and boots. Too, I don't see where the mirrors are 'sexist' (a buzzword that is usually thrown around casually). People who work out usually like to watch themselves in the mirror, and I don't recall the cameraperson oogling the rear-ends of Crusher or Troi....or even their 'chest areas.'
This is why I think the Abrams films are a bit refreshing. They're 'loose' and have personality, they're not afraid of sex. Yes, there are problems (which we have an area dedicated to talking about that down below) but there seems to be 'fun' involved; people are allowed to be 'people.'