TECHNICAL ISSUES MEANS

Technical covers a lot of ground including but not limited to framing/cropping, composition, subject matter, photographic technique, camera angle, depth of field, lighting, color balance, saturation and focus.  If all this means nothing to you, consider enrolling in photography classes.

Refer to these links:
https://helpx.adobe.com/stock/contributor/help/reasons-for-content-rejection.html
https://helpx.adobe.com/stock/contributor/help/quality-and-technical-issues.html

Many people submit their favourite snapshots. Some people even try to use Adobe Stock to teach themselves photography, or submit "my first photo"! But these photos might be used for a million dollar advertising campaign by Adobe's very discerning customers. So, the photos must be of the highest commercial quality, well staged and composed, taken with suitable equipment; post processing is necessary in most cases but much not be obtrusive. Adobe will reject anything imperfect even if the picture is unique and unrepeatable. If you have specific pictures you'd like the experts here to give their opinion on, please share 2-3 EXACTLY AS SUBMITTED (do not resave, as it often hides problems).