I am enjoying the Sidney group's SIG Zoom meetings run by Chas. I know I'm not using my 12month old LG 4K t.v. to its capabilities, i.e. see my iPhoto collection on my desktop or iPad via the older Apple tv box I have. Is there someone who can 'teach' me?
Your Apple TV box is the best way to access your Photo library and desktop, but if your LG smart TV has the "Apple TV" app, then it also has AirPlay 2 -- meaning you can AirPlay any content on a nearby device (like the iPhone or iPad -- a Mac can do this too but it's likely placed too far away unless it is a notebook).
All you should need to do is go to the Control Center on your iOS device (usually a swipe down from the right corner), select the "screen mirroring" control, and then select your LG as one of the options. You'll be asked to verify a code the first time you do this. If you don't have an Apple TV app among your LG's available apps, check for a firmware update -- most LG models should have this.
(and of course you can do this via your Apple TV box just as you already are doing)
While your LG TV has other services it can do without the Apple TV box (such as running Netflix and other services you may subscribe to), generally speaking it is better to do them through your Apple TV device if it is available there, as this reduces data collection quite dramatically and also increases privacy. However, sometimes it is convenient to access a service directly from the LG rather than go through turning on the Apple TV box, et al.