After pointing to this thread, I watched a few YouTube videos. One was a doctor that supposedly worked on some of the first transgender surgeries for kids with malformed male/female parts. Another was about surgeries for adults. The last few were about people who had undergone the surgeries themselves. The point of my mentioning this is that depending on how good the surgeries are, you may not be able to tell by looking or any superficial examination whether they are actually male or female. You'd need a DNA test.
There have been supposed biologically women athletes who have failed hormone test because they didn't have enough female hormones or too many male hormones. Many of the posters here keep referring to the straightness of the hips or size of the hands, or largeness of the ridge above the eyes. Some times these DO help identify male and female. But the truth is there are many people who flat out fail those tests, either because of their own body types, or really well done alterations. Skull bones and adam's apples are often shaved. Other bones can be surgically broken and reset. Some women are naturally more muscular and have deeper voices, while some men have higher voices and less muscles. Many people who do not get the proper nutrients, especially as children, can be extremely difficult to identify as male or female just by looking.
Plus, remember these are internet pictures. Even without photo-shopping, the world of photography exists because pictures can be taken at different angles and with different lighting to produce a bunch of interesting and conflicting results. I remember laughing hysterically that year the "internet controversy" about exactly what color that famous dress was. I laughed until I had an almost identical discussion with a colleague about the color of my own shirt that I had recently purchased. Our disagreement resulted from the way the shirt look in different lighting. Your eyes can lie to you, and media images are specifically designed to take advantage of that fact.
But that doesn't mean that many celebrities are indeed the gender they claim they are. More importantly though, why does it matter? Truthfully, most of the people I hear talking about it are really interested for their own prurient reasons, and they want to make sure the person they are googling were actually born with the parts they prefer.
If that's your only interesting in the topic, TPTB have already won -- your mind has been subverted to useless preoccupations. At that point, it doesn't make if the person is actually male or female, your positive contribution to society has been eliminated, at least for the moment.
Now what about the person is posing as something different than their genes, or is "fluid" in their genetic expression and chooses a gender based on the darts thrown at a wall at 3:17pm Thursday afternoon in their favorite timezone. When people are bombarded enough with this type of mindset, at least a few of them will convince them that claiming female and male identities is as arbitrary as choosing raspberry or vanilla shakes on a hot day. If you get the "right" people convinced of these ideas,
suddenly anyone who presents scientific evidence that that mindset is a bunch of nonsense can now be safely culled from a much more gullible population.