Hi Soozie, Manfred,
The missing pixels are due to TinyPic, it accepts a maximum of 1600 px on longest side, but it you feed it something bigger, it downsizes to 1599 on longest edge (which is handy because it sorta 'proves' when people didn't downsize before upload).
Chapter and verse on image uploading is here, I have done my best to explain it in a logical way for people just trying to get a picture up. The thread structure is first post is an intro and describes the four different ways of doing that, with each of their limitations. Post 6 is useful if you're having image quality problems and explains a bit about why you should do things a certain way for best results. What I am saying is, you don't need to read it all from post 1 - 6 (and beyond) parrot fashion, that won't help you here. Read post 1 (optionally), Post 2 has a Limitations bit for TinyPic that mentions what I said about their max size, but do read post 6 - it explains how and why you should really always downsize an image (and save it as a separate file, not over the original) before uploading to TinyPic - or anywhere really, if you care about viewers seeing your images at their best, particularly sharpness.
HELP THREAD: How can I post images here?
If you have hosted at Flickr, you should be able to link (from a post here) to an image there, not have to also upload it to TinyPic as well.
Speaking generally here (preaching to everyone almost )
It really is not a good idea to upload any image, even a "SOOC" (straight out of camera) one, without first downsizing it. As Manfred says, they come out uncropped with a size like 5184 x 3456.
Now ask yourself a question; how big is a viewer's screen likely to be?
If a modern, separate LCD, the answer is typically 1920 x 1080 (i.e. HD).
If a laptop; typically 1366 x 768.
If a Tablet; typically 1280 x 800.
If you do upload a full size picture somewhere (as I have here)
You can see it won't fit and they have to scroll around, but people don't notice this because their browser will make it fit if presented as a jpg, they may notice it looks soft though when this happens.
For best quality (and this helps make any picture look better on several counts), please, for web display, do yourselves a huge favour and downsize to -
a maximum height of 1000px
and a maximum width of;
1600px if hosting at TinyPic
1900px if hosting where there's no limit
I do my pictures these sizes because it means I can use them as 'wallpaper' and or screen savers on my PC.
There is usually no point uploading a bigger image;
a) it makes CiC threads with big pictures in take MUCH longer to display (impossible for some if they are on dial up) - this is partly why TinyPic limit the size
b) it gives someone else the ability to rip off your work
c) downsizing makes noise better
d) sharpening after downsizing makes sharpness better as long as the viewer can see it at 100%
Really the only reason to upload a fullsize image, as was the case with my example above, is to give people the ability to "pixel peep" a test shot for critical issues like focus, noise and/or lens distortions.
Hope I haven't 'gone on a bit' too long there Soozie, it is a hobby horse I climb on occasionally
(and it obviously isn't all 'aimed' at you)
Hope that helps,