I'm unsure if my girlfriend is keeping something from me...

I'm a 20-year-old female, and my girlfriend, also 20 and female, and I both share our TikTok content. Throughout our one-year relationship, we've been open about checking each other's phones. Recently, I was about to switch to her secondary TikTok account (she has one where she posts regularly and another that she doesn't use), when I noticed a different account that I was already aware of from months ago. At the time, it had no posts or followers. However, when I checked it again, it had gained around 500 likes and some followers. I was intrigued, but the only post on that account had been set to private. It followed a trend called "seeing the TV glow." One comment sought clarification on the meaning of the TikTok, and someone replied that it was related to being transgender. My girlfriend liked those comments that connected to being transgender and dismissing it. One of her comments mentioned that it took her a lot of courage to share the post. The content seemed to express that while she feels comfortable with who she is now, she still occasionally experiences that "glow." What puzzles me is that she never mentioned any of these feelings to me, yet she chose to share them on TikTok. I was planning to approach it casually by asking, "Hey, I noticed your account has 500 likes but no posts. Why didn’t I see anything?" However, when I tried to look up her account to take a screenshot of the likes and followers, it didn’t appear. The username I used was correct, which implies she may have blocked me from seeing the account before she posted anything. If I'm not mistaken, I think I used to follow that account too. Now, I'm at a loss on how to bring this up with her. She has gotten upset with me in the past for checking my phone, but I'm not angry; I’m just confused. Why wouldn’t she share something like this with me, and why block me? I thought we were completely open with each other about everything, even the things we found hard to say. It feels odd that she felt unable to talk to me about this. I’m not entirely sure what I'm seeking in terms of advice, but any thoughts or perspectives would really help.