You’d better check your photo’s aspect ratio if you want people to see all of it without clicking on it. All social media support display of images but they usually truncate them to a standard aspect ratio on the main display such as a Facebook Timeline. This usually means losing the top and bottom of the image, which may contain a caption that you’ve added. However, if your image is in a slideshow, no truncation occurs and the full image is visible. Mobile phone cameras typically take photos with an aspect ratio (ratio of the long side to short side pixel count) of 1.33. Images visible in Facebook Timeline images have an aspect ratio of 1.9 and in landscape mode. So if you have a mobile phone image in portrait mode and you upload it, a lot of the top and bottom of the image will be truncated. Viewers of your post may be able to see the whole image if they click on the image, but if you want people to see the whole image without taking any action, you’d better make sure that the image you post has an appropriate aspect ratio for the social media you are using.
The top picture above shows a captioned portrait orientation mobile phone image with a caption added below which has been padded out to an aspect ratio of 1:1.9 and is now completely visible in Facebook Timeline. The picture beneath it shows the same image with a caption bar beneath it without any padding. Only the centre part is immediately visible. Of course, if you click on it the whole image is shown.